Thanks! That is useful . It seems the last comments on the matter are that fractional scaling is an issue in Wayland and not in X11(with the “pseudi hiDPI” option at least) for RT and they are hoping to make RT compliant with the GTK way of HiDPI and that that ‘should’ take care of Wayland. I guess I have my answer and can ask in the Github issue if I have further queries.
(And for the record I’m not 100% sure what the color fidelity not working under Wayland is since as I mentioned the .icc profile I made via calibration applies the same in Wayland as in X11(after just a little hassle). Could be that there are finer bits in RT that are referred to, well, maybe I’ll reach your level some day in that case 
)