I thought a pollen trap for use with round openings would be pretty cool (think TBH and a soda bottle for the catch container). If the entrance is made right this could double as an active device that kills pest insects trying to use the entrance like hornets, moths, and SHB. A low power laser could do the trick but might also damage the trap. A "ram" that smashes into the bug also ejecting it from the hive would do it!
If you are successful in 3d printing live queens, I would be interested.