Buried within the Debian download directories (which can't currently be accessed because whoever is doing maintenance doesn't understand what a mirror is), is an unofficial live ISO with cinnamon and the non-free firmware - basically the two reasons for wanting Mint.
I hacked with URLs to find 9.5/Stretch (stable) on a mirror - wanted to try 10/Buster (testing) but looks like the weekly releases are only on the offline official servers - though I still need to find a spare USB drive to put it on.
Will be sticking with Gnome, whilst wishing there was more viable variety.
Wish someone would hire me to lead a bunch of Linux developers too; if even half my thoughts could be translated into software the result would be superb.