Hi.
Little explanation here.
Decice can be unlocked from normal mode or from recovery mode, phone must have root acces.
Why we chose unlocking from recovery mode.
When phone start in recovery mode it load separate mini operating system.
This mode is independent and not afect main operating system.
Rooting main operating system is good thing, but it's unsafe for final user(customer) who can delete by mistake(root alow this) some system files
or can reseive some exploits by sms or mail and once phone is rooted, this exploits can affect phone.
From my point of view, clean unlock meen root phone if need, and after unlock unroot, or ask customer if he want rooted phone.
Thanks for usefull help, may be your help will help some users.