I heard complaints about state of UWP FH3 so many times I will look into making azimuth a forza horizon launcher for FH3 as well unless it is too much work and too much drift tech wise from FH2
I really think FH3 would very much benefit from a similar wrapper. The leaked OpusDev build doesn't have the UWP baggage but also isn't on the latest version, missing the last expansion pack but is completely open to modding. The UWP version is a headache, requiring specific Xbox related apps for the game to function and who's to say when later Windows versions will entirely stop supporting it, plus the game files are encrypted, preventing modding without workarounds. Poor performance is also a valid complaint, something they improved on in FH4. There's also some visual issues on the PC version, like rainy wet roads having missing reflections, or certain game resolutions making the entire game screen dimmer. I tried your wrapper with FH2 and I wouldn't be surprised if FH3 with a wrapper would run as well if not better than the native solution, plus it would be open to modding.