based on a quick browsing through the forum Teensyduino should be working on macOS Big Sur, i.e. macOS 11.xx.

But the Web-pages do not list macOS Big Sur as being supported (only macOS versions up to Catalina (10.15) are mentioned.
Would there be a way to clarify on the web-pages if "Big Sur" is supported or not?
In case, that you've concerns about the new HW (i.e. Apple Silicon) just mention it.

As a side note: for Windows 10 there is no limitation which release(s) would be supported, although Windows10 on ARM is probably not supported (at least there doesn't seem to be a download possibility). Not to mention the preview versions...


PS: Arduino states the minimum OS version required ("Win7 and newer", "macOS 10.10 and newer"). That implies that the current OS versions are supported...