Here is latest version of Oneplus Tool . This tool can do almost everything for you. I have added a method to switch the Oem_Unlock switch on Sim locked devices. It will ungray the switch so you can flip it and bootloader unlock. It still has all the other tools like the engineer mode decrypt, to enable the app. Also lots of hidden SECRETS like every oneplus device has a hidden copy of busybox already installed . and this will access it. Plus this has a long list of dialer codes .There are lots of tools like scrcpy and a windows file explorer for your device. I have also added lots of fastboot adb commands. Please feel free to let me know if anything can be added. I been notifided this has been reported as a virus, it is only a .bat file converted to exe. please scan for yourself.
Download: Mega GDrive
Source: XDA Developers