Managed to flash it just to see how it works:
Code:
[info] Found device in Normal mode
[info] iOS version 4.0
[sett] Empty domain com.apple.disk_usage
[sett] Empty domain com.apple.disk_usage.factory
[sett] Empty domain com.apple.mobile.battery
[sett] Empty domain com.apple.iqagent
[sett] Empty domain com.apple.purplebuddy
[sett] Empty domain com.apple.PurpleBuddy
[sett] Empty domain com.apple.MobileAddressBook
[sett] Empty domain com.apple
[sett] Empty domain com.apple.weather
[sett] Empty domain com.apple.Bridge
[sett] Empty domain com.apple.mobile.chaperone
[sett] Empty domain com.apple.mobile.third_party_termination
[sett] Empty domain com.apple.mobile.lockdownd
[sett] Empty domain com.apple.mobile.lockdown_cache
[sett] Empty domain com.apple.xcode.developerdomain
[sett] Empty domain com.apple.international
[sett] Empty domain com.apple.mobile.data_sync
[sett] Empty domain com.apple.mobile.tethered_sync
[sett] Empty domain com.apple.mobile.mobile_application_usage
[sett] Empty domain com.apple.mobile.backup
[sett] Empty domain com.apple.mobile.nikita
[sett] Empty domain com.apple.mobile.restriction
[sett] Empty domain com.apple.mobile.user_preferences
[sett] Empty domain com.apple.mobile.sync_data_class
[sett] Empty domain com.apple.mobile.software_behavior
[sett] Empty domain com.apple.mobile.iTunes.SQLMusicLibraryPostProcessCommands
[sett] Empty domain com.apple.mobile.iTunes.accessories
[sett] Empty domain com.apple.mobile.internal
[sett] Empty domain com.apple.mobile.wireless_lockdown
[sett] Empty domain com.apple.fairplay
[sett] Empty domain com.apple.iTunes
[sett] Empty domain com.apple.mobile.iTunes.store
[sett] Empty domain com.apple.mobile.iTunes
[sett] Reading domain Default
[data] BoardId:24
[data] BuildVersion:15R607
[data] ChipID:32772
[data] DeviceClass:Watch
[data] DeviceColor:1
[data] DeviceName:Apple Watch
[data] DieID:6300055681822502
[data] HardwareModel:N121sAP
[data] PartitionType:GUID_partition_scheme
[data] ProductName:Watch OS
[data] ProductType:Watch3,3
[data] ProductVersion:4.0
[data] ProductionSOC:TRUE
[data] ProtocolVersion:2
[data] TelephonyCapability:FALSE
[data] UniqueChipID:6300055681822502
[data] UniqueDeviceID:43c09fd3e02cfd648fbd713f6fd486e70a76fc10
[data] UntrustedHostBUID:307503182012896990138287868
[data] WiFiAddress:98:00:c6:1b:48:58
[sett] Reading sparse data...
[data] ChipID:32772
[data] DeviceName:Apple Watch
[data] DeviceColor:1
[data] DeviceEnclosureColor:2
[data] CertificateProductionStatus:TRUE
[data] CertificateSecurityMode:TRUE
[data] DeviceClass:Watch
[data] BuildVersion:15R607
[data] ProductName:Watch OS
[data] ProductType:Watch3,3
[data] ProductVersion:4.0
[data] ProtocolVersion:2
[data] ProductionSOC:TRUE
[data] ActiveWirelessTechnology:kCTWirelessTechnologyUnknown
[data] TelephonyCapability:FALSE
[data] DeviceSupportsFaceTime:TRUE
[data] EffectiveProductionStatusAp:TRUE
[data] EffectiveProductionStatusSEP:FALSE
[data] EffectiveSecurityModeAp:TRUE
[data] EffectiveSecurityModeSEP:FALSE
[data] HasSEP:TRUE
[data] UniqueDeviceID:43c09fd3e02cfd648fbd713f6fd486e70a76fc10
[data] UniqueChipID:6300055681822502
[data] MixAndMatchPrevention:TRUE
[data] DevicePublicKey:binary data type
[data] PartitionType:GUID_partition_scheme
[data] WiFiAddress:98:00:c6:1b:48:58
[info] DiagData saved to C:\Program Files (x86)\MFC\iBackups\43c09fd3e02cfd648fbd713f6fd486e70a76fc10\DiagData_2021-11-18T12_51_15Z.bin
[data] DiagData:binary data type
[info] SysCfgData saved to C:\Program Files (x86)\MFC\iBackups\43c09fd3e02cfd648fbd713f6fd486e70a76fc10\SysCfgData_2021-11-18T12_51_15Z.bin
[data] SysCfgData:binary data type
[info] Data saved to C:\Program Files (x86)\MFC\iBackups\43c09fd3e02cfd648fbd713f6fd486e70a76fc10\read_info.plist
[info] Identified device as Apple Watch S3, n121sap, Watch3,3
[done] Operation finished!
[info] Updated version data.
[info] Found device in Normal mode
[info] Gettting normal mode device ...
[info] Identified device as Apple Watch S3, n121sap, Watch3,3
[erro] Can't find major version?!
[erro] can't get URL for latest firmware
[done] Operation finished!
[info] device disconnect...
[info] device arrival... new
[info] Using LOCAL IPSW D:\MFCBOX\iWatch Firmware\MFC_Watch3,3_8.1_19R570_n121sAP_GPS_Restore_38mm.ipsw
[info] using cached version data
[info] Found device in Normal mode
[info] Gettting normal mode device ...
[info] Identified device as Apple Watch S3, n121sap, Watch3,3
[info] Extracting BuildManifest from ipsw
[data] Product Version: 8.1
[data] Product Build: 19R570 Major: 19
[data] Device supports Image4: true
[info] Variant: Customer Erase Install (IPSW)
[info] This restore will erase your device data.
[info] Checking IPSW for required components...
[info] All required components found in IPSW
[info] Found ECID 001661de04faef26
[info] Getting ApNonce in normal mode... [data] 6DE1A9D5AA84426C06EE0A54DDFACD77E3B1941848F60F9F9113EF1A21715E6A
[info] tts>Trying to fetch new SHSH blob
[info] Getting SepNonce in normal mode... [data] DBA84E1612325A174CCF1B9238400B3AEF0AC37F
[note] Unable to find BbChipID node
[note] Unable to find BbProvisioningManifestKeyHash node
[note] Unable to find BbActivationManifestKeyHash node
[note] Unable to find BbCalibrationManifestKeyHash node
[note] Unable to find BbFactoryActivationManifestKeyHash node
[note] Unable to find BbFDRSecurityKeyHash node
[note] Unable to find BbSkeyId node
[erro] Unable to get FirmwarePreflightInfo
[info] Request URL set to https://gs.apple.com/TSS/controller?action=2
[info] Sending TSS request attempt 1...
[info] response successfully received
[info] tts>Received SHSH blobs
Filesystem file not found!
We will extract the filesystem to file iDeviceTools/MFC_Watch3,3_8.1_19R570_n121sAP_GPS_Restore_38mm/018-59029-081.dmg
[info] Extracting filesystem
[info] Found ECID 001661de04faef26
[info] Getting ApNonce in normal mode... [data] 6DE1A9D5AA84426C06EE0A54DDFACD77E3B1941848F60F9F9113EF1A21715E6A
[info] tts>Trying to fetch new SHSH blob
[info] Getting SepNonce in normal mode... [data] 5213971C4386FA62E0FC274144B9652395E8853B
[note] Unable to find BbChipID node
[note] Unable to find BbProvisioningManifestKeyHash node
[note] Unable to find BbActivationManifestKeyHash node
[note] Unable to find BbCalibrationManifestKeyHash node
[note] Unable to find BbFactoryActivationManifestKeyHash node
[note] Unable to find BbFDRSecurityKeyHash node
[note] Unable to find BbSkeyId node
[erro] Unable to get FirmwarePreflightInfo
[info] Request URL set to https://gs.apple.com/TSS/controller?action=2
[info] Sending TSS request attempt 1...
[info] response successfully received
[info] tts>Received SHSH blobs
[info] Entering recovery mode...
[info] device disconnect...
[info] device serial number is FHLV8PWEJ5X0
[warn] No path for component iBEC in TSS, will fetch from build_identity
[info] Extracting iBEC.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component iBEC...
[info] Sending iBEC (769060 bytes)...
[info] Device ecid 001661de04faef26 disconnect detected!
[info] Recovery Mode Environment:
[info] iBoot build-version=iBoot-7429.40.94
[info] iBoot build-style=RELEASE
[info] Sending AppleLogo...
[warn] No path for component AppleLogo in TSS, will fetch from build_identity
[info] Extracting applelogo@115~watch.im4p...
[info] Personalizing IMG4 component AppleLogo...
[info] Sending AppleLogo (8783 bytes)...
[warn] No path for component RestoreTrustCache in TSS, will fetch from build_identity
[info] Extracting 018-59001-088.dmg.trustcache...
[info] Personalizing IMG4 component RestoreTrustCache...
[info] Sending RestoreTrustCache (15580 bytes)...
[warn] No path for component RestoreRamDisk in TSS, will fetch from build_identity
[info] Extracting 018-59001-088.dmg...
[info] Personalizing IMG4 component RestoreRamDisk...
[info] Sending RestoreRamDisk (84181346 bytes)...
[warn] No path for component RestoreDeviceTree in TSS, will fetch from build_identity
[info] Extracting DeviceTree.n121sap.im4p...
[info] Personalizing IMG4 component RestoreDeviceTree...
[info] Sending RestoreDeviceTree (32385 bytes)...
[warn] No path for component RestoreSEP in TSS, will fetch from build_identity
[info] Extracting sep-firmware.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component RestoreSEP...
[info] Sending RestoreSEP (2480706 bytes)...
[warn] No path for component RestoreKernelCache in TSS, will fetch from build_identity
[info] Extracting kernelcache.release.watch3...
[info] Personalizing IMG4 component RestoreKernelCache...
[info] Sending RestoreKernelCache (14362922 bytes)...
[info] Device ecid 001661de04faef26 disconnect detected!
[info] About to restore device...
[info] Waiting for device...
[info] Device is now connected in restore mode...
[info] Connecting now...
[info] Connected to com.apple.mobile.restored, version 15
[info] Device 43c09fd3e02cfd648fbd713f6fd486e70a76fc10 has successfully entered restore mode
[info] Hardware Information:
[info] BoardID: 24
[info] ChipID: 32772
[info] UniqueChipID: 6300055681822502
[info] ProductionMode: true
[info] Starting FDR listener thread
[info] Connecting to FDR client at port 1082
[warn] About to do ctrl handshake
[done] Ctrl handshake done (ConnPort = 49170)
[warn] Requesting NOT TO Update Baseband
[info] Checkpoint 1621 complete with code 0
[info] Checkpoint 1540 complete with code 0
[info] Checkpoint 1679 complete with code 0
[info] About to send RootTicket...
[info] Sending RootTicket now...
[info] Done sending RootTicket
[info] Checkpoint 1547 complete with code 0
[info] Waiting for NAND (28)
[info] Checkpoint 1549 complete with code 0
[info] Checkpoint 1550 complete with code 0
[info] Checkpoint 1551 complete with code 0
[info] Checkpoint 1628 complete with code 0
[info] Checkpoint 1552 complete with code 0
[info] Checkpoint 1555 complete with code 0
[info] Checkpoint 1662 complete with code 0
[info] Sending NORData...
[info] Found firmware path Firmware/all_flash
[erro] zip_name_locate: Firmware/all_flash/manifest
[info] Getting firmware manifest from build identity
[info] Extracting LLB.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component LLB...
[info] Extracting applelogo@115~watch.im4p...
[info] Personalizing IMG4 component AppleLogo...
[info] Extracting dali-ui.n121s.release.im4p...
[info] Personalizing IMG4 component Dali...
[info] Extracting DeviceTree.n121sap.im4p...
[info] Personalizing IMG4 component DeviceTree...
[info] Extracting recoverymode@115~watch.im4p...
[info] Personalizing IMG4 component RecoveryMode...
[info] Extracting iBoot.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component iBoot...
[info] Extracting sep-firmware.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component RestoreSEP...
[info] Extracting sep-firmware.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component SEP...
[info] Sending NORData now...
[info] Done sending NORData
[info] Checkpoint 1545 complete with code 0
[info] Checkpoint 1683 complete with code 0
[info] Unmounting filesystems (29)
[info] Checkpoint 1637 complete with code 0
[info] Checkpoint 1556 complete with code 0
[info] Checkpoint 1686 complete with code 0
[info] Checkpoint 1697 complete with code 0
[info] Checkpoint 1695 complete with code 0
[info] Checkpoint 1620 complete with code 0
[info] Checkpoint 1687 complete with code 0
[info] Checkpoint 1557 complete with code 0
[info] About to send FDR Trust data...
[info] Sending FDR Trust data now...
[done] sending FDR Trust Data
[info] Checkpoint 1558 complete with code 0
[info] Checkpoint 1559 complete with code 0
[info] Checkpoint 1560 complete with code 0
[info] Checking for uncollected logs (44)
[info] Checkpoint 1561 complete with code 0
[info] Checking for uncollected logs (44)
[info] Checkpoint 1562 complete with code 0
[info] Connecting to FDR client at port 49170
[info] Checkpoint 1563 complete with code 0
[info] Checkpoint 1633 complete with code 0
[info] Unmounting filesystems (29)
[info] Checkpoint 1565 complete with code 0
[info] Checkpoint 1614 complete with code 0
[info] Checkpoint 1567 complete with code 0
[info] Checkpoint 1674 complete with code 0
[info] Creating partition map (11)
[info] Checkpoint 1569 complete with code 0
[info] Checkpoint 1632 complete with code 0
[info] Checkpoint 1570 complete with code 0
[info] Checkpoint 1629 complete with code 0
[info] Checkpoint 5645 complete with code 0
[info] Creating filesystem (12)
[info] Checkpoint 1624 complete with code 0
[info] Checkpoint 1625 complete with code 0
[info] Checkpoint 1626 complete with code 0
[info] About to send filesystem...
[info] Connected to ASR
[info] Validating the filesystem
[info] Filesystem validated
[info] Sending filesystem now...
[done] sending filesystem
[info] Operation: Verifying restore (14)
[info] Checkpoint 1627 complete with code 0
[info] Checkpoint 1664 complete with code 0
[info] Checkpoint 1653 complete with code 0
[info] Checkpoint 1676 complete with code 0
[info] Unmounting filesystems (29)
[info] Checking filesystems (15)
[info] Mounting filesystems (16)
[info] Checkpoint 1574 complete with code 0
[info] Checkpoint 1634 complete with code 0
[info] Checkpoint 1655 complete with code 0
[info] Checkpoint 1658 complete with code 0
[info] Checkpoint 1575 complete with code 0
[info] Checkpoint 1690 complete with code 0
[info] Checkpoint 1691 complete with code 0
[info] Checkpoint 1618 complete with code 0
[info] Checkpoint 1588 complete with code 0
[info] Checkpoint 1661 complete with code 0
[info] Operation: Updating AppleTCON (81)
[info] Sending IsiBootEANFirmware image list
[info] Sending IsiBootNonEssentialFirmware image list
[info] Flashing firmware (18)
[info] Checkpoint 4864 complete with code 0
[info] Operation: Updating AppleTCON (81)
[info] Sending IsEarlyAccessFirmware image list
[info] Sending IsiBootEANFirmware image list
[info] Sending IsiBootNonEssentialFirmware image list
[info] Checkpoint 4882 complete with code 0
[info] Operation: Requesting FUD data (36)
[info] Found IsFUDFirmware component ACIBT
[info] Found IsFUDFirmware component ACIWIFI
[info] Found IsFUDFirmware component AOP
[info] Found IsFUDFirmware component Ap,SystemVolumeCanonicalMetadata
[info] Found IsFUDFirmware component Multitouch
[info] Found IsFUDFirmware component RTP
[info] Found IsFUDFirmware component RestoreTrustCache
[info] Found IsFUDFirmware component StaticTrustCache
[info] Found IsFUDFirmware component SystemVolume
[info] Sending IsFUDFirmware image list
[info] Extracting BT_FW.im4p...
[info] Personalizing IMG4 component ACIBT...
[info] Sending IsFUDFirmware for ACIBT...
[info] Extracting wifi_armv7r_m8p_rtkit_image.im4p...
[info] Personalizing IMG4 component ACIWIFI...
[info] Sending IsFUDFirmware for ACIWIFI...
[info] Extracting aopfw-m8paop.im4p...
[info] Personalizing IMG4 component AOP...
[info] Sending IsFUDFirmware for AOP...
[info] Extracting 018-59029-081.dmg.mtree...
[info] Personalizing IMG4 component Ap,SystemVolumeCanonicalMetadata...
[info] Sending IsFUDFirmware for Ap,SystemVolumeCanonicalMetadata...
[info] Extracting N121s_Multitouch.im4p...
[info] Personalizing IMG4 component Multitouch...
[info] Sending IsFUDFirmware for Multitouch...
[info] Extracting rtpfw.im4p...
[info] Personalizing IMG4 component RTP...
[info] Sending IsFUDFirmware for RTP...
[info] Extracting 018-59001-088.dmg.trustcache...
[info] Personalizing IMG4 component RestoreTrustCache...
[info] Sending IsFUDFirmware for RestoreTrustCache...
[info] Extracting 018-59029-081.dmg.trustcache...
[info] Personalizing IMG4 component StaticTrustCache...
[info] Sending IsFUDFirmware for StaticTrustCache...
[info] Extracting 018-59029-081.dmg.root_hash...
[info] Personalizing IMG4 component SystemVolume...
[info] Sending IsFUDFirmware for SystemVolume...
[info] Checkpoint 4874 complete with code 0
[info] Updating gas gauge software (47)
[info] Checkpoint 4865 complete with code 0
[info] Updating gas gauge software (47)
[info] Checkpoint 4866 complete with code 0
[info] Updating Stockholm (55)
[info] Checkpoint 4868 complete with code 0
[info] Operation: Requesting FUD data (36)
[info] Found IsFUDFirmware component ACIBT
[info] Found IsFUDFirmware component ACIWIFI
[info] Found IsFUDFirmware component AOP
[info] Found IsFUDFirmware component Ap,SystemVolumeCanonicalMetadata
[info] Found IsFUDFirmware component Multitouch
[info] Found IsFUDFirmware component RTP
[info] Found IsFUDFirmware component RestoreTrustCache
[info] Found IsFUDFirmware component StaticTrustCache
[info] Found IsFUDFirmware component SystemVolume
[info] Sending IsFUDFirmware image list
[info] Extracting 018-59029-081.dmg.mtree...
[info] Personalizing IMG4 component Ap,SystemVolumeCanonicalMetadata...
[info] Sending IsFUDFirmware for Ap,SystemVolumeCanonicalMetadata...
[info] Extracting 018-59001-088.dmg.trustcache...
[info] Personalizing IMG4 component RestoreTrustCache...
[info] Sending IsFUDFirmware for RestoreTrustCache...
[info] Extracting 018-59029-081.dmg.root_hash...
[info] Personalizing IMG4 component SystemVolume...
[info] Sending IsFUDFirmware for SystemVolume...
[info] Checkpoint 4869 complete with code 0
[info] Checkpoint 4870 complete with code 0
[info] Checkpoint 4871 complete with code 0
[info] Checkpoint 4872 complete with code 0
[info] Checkpoint 4878 complete with code 0
[info] Checkpoint 4879 complete with code 0
[info] Checkpoint 4875 complete with code 0
[info] Checkpoint 4867 complete with code 0
[info] Checkpoint 4880 complete with code 0
[info] Updating SE Firmware (59)
[info] Extracting Stockholm4.RELEASE.sefw...
[note] Unable to find BbChipID node
[note] Unable to find BbProvisioningManifestKeyHash node
[note] Unable to find BbActivationManifestKeyHash node
[note] Unable to find BbCalibrationManifestKeyHash node
[note] Unable to find BbFactoryActivationManifestKeyHash node
[note] Unable to find BbFDRSecurityKeyHash node
[note] Unable to find BbSkeyId node
[info] Sending SE TSS request...
[info] Request URL set to https://gs.apple.com/TSS/controller?action=2
[info] Sending TSS request attempt 1...
[info] response successfully received
[info] Received SE ticket
[info] Sending FirmwareResponse data now...
[info] Done sending FirmwareUpdater data
[info] Checkpoint 4873 complete with code 0
[info] Unknown operation (80)
[info] Checkpoint 4886 complete with code 0
[info] Checkpoint 1589 complete with code 0
[info] Checkpoint 1596 complete with code 0
[info] Checkpoint 5379 complete with code 0
[info] Unknown operation (75)
[info] Checkpoint 5380 complete with code 0
[info] Checkpoint 4884 complete with code 0
[info] Checkpoint 1640 complete with code 0
[info] Checkpoint 1597 complete with code 0
[info] Checkpoint 1647 complete with code 0
[info] Resizing Main Filesystem Partition (68)
[info] Checkpoint 1652 complete with code 0
[info] Checkpoint 1631 complete with code 0
[info] About to send KernelCache...
[warn] No path for component KernelCache in TSS, will fetch from build identity
[info] Extracting kernelcache.release.watch3...
[info] Personalizing IMG4 component KernelCache...
[info] Sending KernelCache ...
[info] Done sending KernelCache[info] Installing kernelcache (27)
[info] Checkpoint 3584 complete with code 0
[info] About to send DeviceTree...
[warn] No path for component DeviceTree in TSS, will fetch from build identity
[info] Extracting DeviceTree.n121sap.im4p...
[info] Personalizing IMG4 component DeviceTree...
[info] Sending DeviceTree ...
[info] Done sending DeviceTree[info] Installing DeviceTree (61)
[info] Checkpoint 3585 complete with code 0
[info] Sending NORData...
[info] Found firmware path Firmware/all_flash
[erro] zip_name_locate: Firmware/all_flash/manifest
[info] Getting firmware manifest from build identity
[info] Extracting LLB.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component LLB...
[info] Extracting applelogo@115~watch.im4p...
[info] Personalizing IMG4 component AppleLogo...
[info] Extracting dali-ui.n121s.release.im4p...
[info] Personalizing IMG4 component Dali...
[info] Extracting DeviceTree.n121sap.im4p...
[info] Personalizing IMG4 component DeviceTree...
[info] Extracting recoverymode@115~watch.im4p...
[info] Personalizing IMG4 component RecoveryMode...
[info] Extracting iBoot.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component iBoot...
[info] Extracting sep-firmware.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component RestoreSEP...
[info] Extracting sep-firmware.n121s.RELEASE.im4p...
[info] Personalizing IMG4 component SEP...
[info] Sending NORData now...
[info] Done sending NORData
[info] Checkpoint 3588 complete with code 0
[info] Checkpoint 3589 complete with code 0
[info] Checkpoint 3587 complete with code 0
[info] Checkpoint 1576 complete with code 0
[info] Fixing up /var (17)
[info] Creating system key bag (50)
[info] Checkpoint 3840 complete with code 0
[info] Checkpoint 3841 complete with code 0
[info] Checkpoint 3844 complete with code 0
[info] Connecting to FDR client at port 49170
[info] Checkpoint 3849 complete with code 0
[info] Checkpoint 1613 complete with code 0
[info] Checkpoint 1694 complete with code 0
[info] Checkpoint 1595 complete with code 0
[info] Modifying persistent boot-args (25)
[info] Checkpoint 1593 complete with code 0
[info] Checkpoint 1630 complete with code 0
[info] Checkpoint 1672 complete with code 0
[info] Checkpoint 1659 complete with code 0
[info] Checkpoint 5632 complete with code 0
[info] Checkpoint 1599 complete with code 0
[info] Checkpoint 1600 complete with code 0
[info] Checkpoint 1675 complete with code 0
[info] Checkpoint 1641 complete with code 0
[info] Unmounting filesystems (29)
[info] Checkpoint 1602 complete with code 0
[info] Checkpoint 1660 complete with code 0
[info] Checkpoint 5651 complete with code 0
[info] Checkpoint 1607 complete with code 0
[info] Status message: Restore Finished
[info] Cleaning up...
[done] Done
[done] Operation finished!