I'm not sure what issues in Wayland you're talking about. I've been using sway with fractional scaling for a few years now and never really had any problems.
This sounds like a really attractive idea until you realize that a 1.25x 1080p screen means you’re now rendering everything at 3K resolution, including any and all games.
Additionally compositors often scale directly in sRGB, which means you’re introducing lots of gamma errors.