Changing the architecture is almost a nonsense
You are very wrong, Vincent. There were and are many people with CT60/030 setup and personally, I often (used to) switch from Aranym to Falcon setup when testing some things.
In the same spirit, on Linux when upgrading the kernel, it is very common to keep the older one as backup if something goes wrong on the newer one. Then GRUB (the boot menu) can easily be used to select one kernel or another.
This is already done -- with -CUR and -X-YZ-W suffixes. Trouble is the release cycle is so rare everybody uses -CUR whenever possible :)