Missing Parameters onto the Fly display. RPM, Waypoint

Hi, Using and liking QGC on SteamDeck for an ArduRover mower.
I have RTK working with SNIP via mavproxy, video working well.

Hoping for a bit of help to get the Steamdeck/QGC replacing RC Control/MPlanner

  1. Missing Parameters - eg RPM and MAV_ mavlink parameters are not displayed on the screen or have options. How to add them to the display if they arent in any categories ? Waypoint is missing also i think

  2. Joystick. Assigning “Hold” to a button works - but subsequent pressing the button has no effect. This is a show stopper as 250kg rovers not stopping is a concern. How to troubleshoot. I note the disarm button has a dialogue - are you sure (good idea for a copter, not for a rover)

Thanks in advance.