It occurred to me last night that it might be possible to make many variations of a rootfs in KLs without running in RAM2.
@fredx181's upper_changes backup script seems to be working perfectly. I have used the restore function, as well as simply manually renaming the backup back to upper_changes.
So I was thinking I'd develop a new base system of recent KL releases by:
1) unpacking the rootfs and doing a psuedo-full install and boot normally not using RAM2
2) run restore-sys to save backups of the upper_changes along the way that would now contain the entire rootfs+changes
3) rename and resquash them as 07rootfs on the fly, which can be done without rebooting.
This got me thinking that it's possible to simply always run as psuedo-full install while creating updated root filesystems as desired. Not as clean as building from a script, but perhpas still practical from the standpoint of a user such as myself who is always tweaking and updating on the go.
If the PFI upper_changes get bungled at some point, simply roll back. Admittedly, takes up a lot more disk space than using upper_changes the way they were intended.