The keyboard shortcut mapping for mouse buttons is super helpful when connecting to a Windows PC since the shortcuts of Windows and MacOS vary a lot. For example, I usually bind the forward and backward buttons with Opt+Left and Opt+Right for Microsoft Remote Desktop, which functions as Alt+Left and Alt+Right.

This used to work well with my my G Pro mouse but does not work with a newly bought MX Master 3S.

I tried to do a keyboard on the remote PC. It skipped Alt and only got left and right.