Locking the file
/union/etc/X11/xorg.conf
will maintain the settings during reboots.
I think the fstab file is written at each boot also.
Not surprising that those two are written at boot ..... it is the desirable behaviour when booting in different hardware.
It seems that the persistence settings do not override them.
the xorg.conf issue is specifically related to some (less common) resolution, at least there is a workaround.
the fstab, yes it's managed in a different way
from mylivecd, (system was supposed to run from ISO read-only media).
mylivecd provide an option for fstab:
--fstab <options> Override the default options for the fstab on
the LiveCD. Options are one or more of 'auto'
and 'rw', for example '--fstab=rw,auto' will
automatically mount all detected partitions
rw.
We need to investigate a little around that option.

AS