Thanks so much for the detailed and helpful reply!
I agree a single linux home+root+boot partition suffices for my need, understand re the /boot/efi setup, understand re swap on ssd, the foss link helps, and your additional advice is appreciated.
All really helpful stuff you've provided!
Specific to the GPC Micro PC (whose web site specifically mentions Mate 19.10), is there any additional process involved with that end of the installation, or is the as-downloaded install image sufficient for the GPC Micro PC?
Dave