I tried to play with the mouse and keyboard, but only the keyboard worked and I couldn't look around with the mouse.
Logitech MK270 mouse and keyboard combo ($20 USD everywhere) works great on my Xbox Series X. It has a unified USB-A dongle and both M&K connect, so only 1 USB port is taken up. The mouse does work in TSW2, but for some reason I can't actually move clickable stuff in train cabs (e.g. I can click on a throttle with the mouse, but I can't actually move the throttle using the mouse), so I rarely actually bother to use the mouse. Most, if not all, of the keyboard commands seem to work on Xbox. However, there's no way to view the keyboard commands in-game, so you need to capture these from elsewhere. I've contemplated making little cheatsheets to cut out and tape to each key, since I only use this keyboard for TSW2. My actual usage of the keyboard boils down to the FPS meter, toggling of various views, screenshotting, and using the fast free cam of holding shift key while I move the camera with my controller's stick.
Good point and remember the keyboard is going to be useful for the German and Future ÖBB routes because you have access to PZB Override Befehl 40 PZB Frei PZB Release & PZB Wachasm Acknowledge. Reason for this is that you don't have to use operation shift on immersion controls to access PZB Override and release. However you cannot use the train brake use the controller for that. Control Shift Enter turns on all train protection systems Keyboard console. F key increase cruise control R key decrease cruise control. On the DR BR243 DB BR143 that means Force Selector since Speed control is operated by A key increase speed D key Decrease speed. other locomotives Power increase / decrease