This update removes the Windows 11 restriction from the installer.
Thanks to the work of the community getting WSA running on Windows 10, WSA Sideloader can now be used on Windows 10.
I however cannot guarantee this will work properly since WSA on Windows 10 is not supported by Microsoft, but I have tested it with WSA 2301.40000.4.0 from WSABuilds on Windows 10 22H2 (Build 19045.2546) and it seems to be working. If WSA can accept ADB commands correctly, then I believe WSA Sideloader should work just fine.
This restriction will only be lifted for the downloadable EXE release from GitHub, as well as winget. MS Store version will continue to be limited to Windows 11 only, and thus will not be getting this update and will remain on 1.3.10.
UPDATE (11 March 2023): Native ARM64 version is now available!