I just wanted to say thanks for this. I'm looking into getting a button box and had a few questions. This post answered almost all of them before I even had a chance to ask. One thing I was wondering about was the rotary encoders and how they functioned. Based on this, it seems like they would be great for brake bias and ARB adjustments. One knob would take the place of two pushbuttons.
Also I couldn't figure out a use for the joystick but adjusting the seat is a great idea.
As for mounting, what I'm thinking about doing is using a clamp-on swivel mount for a tablet. Something like this: https://www.rammount.com/part/RAP-40...Specs-Features. That one is expensive but it's made for heavy-duty applications like mounting stuff on a boat or truck.
The macro capability could be useful for manipulating the ICM menu.