I wonder whether Orbiter runs well on ARM devices or not, including both Windows and Mac. I'm asking this to the forum since Orbiter isn't listed in the otherwise community-maintained Software Compatibility List for Windows ARM, and the discussions on Mac support are mostly on Intel Macs (pre-Apple Silicon). Also, I'm considering a switch from Windows x86/x64 to macOS or Windows ARM for professional reasons if all my software works there.

Never tried it. I am not even sure if the APIs exist on Windows ARM, that we use. I suspect, it will require some rework - and thus dedicated developers and maintainers to make such a project more than just a once-in-a-lifetime experiment.