Keepers for the MMU tension springs/bolts so you don't have to crawl on the floor if you flip open the device.
Drilled out and added setscrew to make it easier to work on selector:
This is something that could have a captive but or at least a hole to thread into. It works as is but I assume it is a little delicate since there isn't a lot of plastic there.
Finally I added a Reset Button which doesn't have you looking for just the right thing to use each time, worrying about poking metal into the USB port on accident, etc.
And there's my already posted, but the Best upgrade I've done yet:
I've gone as far as attaching the cardboard with tape because the clamps are ugly and I don't need to take the device apart as much as I was afraid of. This particular one has a strong need for a V2 to be more visually appealing, but it works great and took my printer for rarely working to rarely failing.
I would love to see others' modifications, and hopefully by interacting we can improve collaboratively.