I believe the only way to firmware up an Xbox controller is on an Xbox or through the Xbox Accessories app on Windows. I’ve been using my work laptop to update my Xbox controllers.

As an alternative, some of the 8bitdo controllers are in LVFS, and I’ve heard the PlayStation Controller Firmware Updater works in WINE for DualShock and DualSense controllers.

Steam is putting out the end of year summaries. You should see it in Steam.