Oh, actually not yet. That's surprising as in general I think Intel graphics tend to have the best compatibility out there. Currently main workstation on amdgpu on a 5xxxG - I'm still not sure if I've gotten the hardware transcoding etc working properly but that's all unrelated to fractional scaling, I assume.
Even with Intel graphics? I have stumbled on a number of showstopping bugs and moved back to X, which is also pretty horrible...