This thread talks though the issue (answered) Install /e/ on FP5 with newer Security Patches.
Never mind build dates,
never mind Vendor security patch dates.
There are two significant dates only
and “Never go back”.
- Android SPL on the device originally at time of unlock
- Android SPL of the /e/OS build you installed and intend to lock.
2 can be equal or newer than 1.
A discussion about bootloader locking/unlocking… AKA I want to relock my bootloader, should I?
When you talk of backup, there are extra precautions one must take if you lock the bootloader after a period of use. There precautions are mentioned in [HOWTO] a Safe Guide to install "IMG-e-builds" even if the /e/ web installer fails.