If reverting somehow using XENTRY then it is all factory firmware, no?

 

Prolly, but I really don't know so your guess is as good as mine. Maybe someone will try it.

 

If it is like phones that have irreversible firmware due to the computer checking and comparing bootloaders, for higher bootloader version (likely controlled by an e-fuse and will be tripped if something is installed, even at low level software) then... yes probably can't revert it. Aftermarket wise, probably doable.