Thanks, @gapan.
I followed your excellent instructions and all is well.
That's a decent intro to chroot by itself!
Just need to find the acpi for my thinkpad battery and see if the cameras work...

Keep up the good work, Team Salix

Hi all, had a look for a solution but seem to be the only one...

Using USB installer - all appears to work onto a mmc with a fresh gpt and partitions as suggested (300MB EFI, 40GB /, 8GB swap, the rest /home).
On reboot I get the (familiar to some over the years) 'can't mount root at unknown (0,0 ...