It's been a few years now, but I was able to repair a thumbwheel by gluing it and then wedging some small pieces of wood under the frame to help support it when pressing the thumbwheel. I applied hot glue to hold the shims in place.
I then ordered a new thumbwheel, but the fix worked well so I just left it. It lasted over a year until I dropped the remote and knocked the shims loose from the hot glue. Had to take it apart again so I replaced the thumbwheel with the one I had ordered at that time.
Without taking the remote apart again, I can't remember exactly where I put the shims? It was somewhere to support the frame to prevent it from flexing when the wheel was pressed. I think you will see the spot when you get inside the remote and see how it flexes.
I was also hoping to order some more of the thumbwheels when they got them, sure hope the come up with something! I much prefer the remote as well!
The added side button shown above is a really good idea, I like that. May look into that myself, thanks for posting!
