I have Stellarmate running on some rPi4 and am also running kstars/ekos on Intel mini pcs and was wondering if there is a simple way to switch the mini pcs to Stellarmate-X without doing clean installs and losing all my settings and other installed software. I might want to mess with the EAA options of Stellarmate and iPad control which isn’t possible with the Ubuntu installs.

Maybe you could give a shot with Timeshift.

Did you have any luck with this? I also have kstars / ekos running on an existing astro mini pc. I want to do EAA / live stacking so I'm looking into Stellarmate X OS for mini PC.

It would be nice to be able to update my sources.list and install Stellarmate that way.

I haven’t found a shortcut and also haven’t found if Stellarmate will work in dual boot with grub so am still on Ubuntu.

I haven't tried to install it yet (haven't pulled the trigger) so I don't know if the installer allows you to manage your partitions and install target. That would be the major hurdle for dual booting and you could deal with grub yourself if you had to after that.