Given that there are 4 commercial breaks per episode, I’m not sure if we could come up with 52 different fan designed invention exchanges to fill those slots. But I’d be willing to give it a shot.
I’ve already got 4 of them that you can see in this thread, including Celebrity Sourdough Starters, Hexting, The Stand-Up Sit-Down Meal, and The After-Dinner Ejector Seat.
Personally I think episode premieres should be proceeded by a pre-show… which could include all sorts of fan submitted content, everything from letters to cosplay photos to full on invention exchanges.