The Simple DirectMedia Library that is widely-used by many cross-platform games and part of the Steam Runtime now has better support for handling more mouse button events under Wayland.
Last week was a bug report over supporting more mouse buttons than five. While some mice end up binding their extra mouse buttons to keyboard keys, some mice such as when configured via Libratbag+Piper can map them to higher key press input event codes. Theoretically, allowing up to 48 key press input events in total.
Now that I think about it, I’m realising I didn’t set it up specifically after switching from windows. It just kept doing the same things I set up before. It does mostly imitate keyboard input though, except for the ones I set as mouse actions (rapid L/R clicks) which still does that. Maybe the designers actually gave it some memory of its own. And yeah, the extra button use has all been in gaming so the proton/xwayland thing would make sense.
Gaming peripherals usually have internal memory for settings, yeah.
When you edit what a button does, it actually changes the input sent by the device in the firmware, so your mouse is likely just pretending to be a keyboard for those keys, and just internally running macros for the autoclicks.
It’s why you can set things up, and then close the config software.