Yeah, except I guess 98% of HiDPI users are on MacOS, a platform they are currently unable to create builds for.
I messed up some PAM config shortly after, and had to chroot to fix it - couldn't read a single letter I was typing (impossibly small and distorted for the number of pixels used to display them, character widths all over the place too) but manager to get it done, very carefully and slowly...
I probably should've made getting it working system wide a priority after that (maybe it's as simple as I used my user config rather than /etc, I can't remember) but I haven't. I suppose worst case I could use a different older monitor anyway.
Looking forward to seeing Gimp with native support though