It looked like it was pressing up instead of down, but I figure it was just an adjustment needed.

 

On his particular setup, I believe he just has it Velcroed to the panel. Not using any mods to the device.

 

That's what I figured was done, and likely what I'd be doing if I try this. It's so simple, I'm sorry I didn't think of it.

Only issue I see is where to mount it in the DII so it would get button presses. I may need to create a mount for it where I've currently got it mounted that it can press against. Just have to figure out how to make the mount solid enough.