Not sure if you have seen it but the FAA have proposed new rules for UAVs that will require remote transponders. This can have many consequences for drone pilots including additional costs and can really harm hobbyist and commercial drone usage. You can find more information and a link to give comments back to the FAA on the article below.
The FAA Proposed Rule On Remote Identification Will Kill Drone Flying
The FAA Proposed Rule On Remote Identification Will Kill Drone Flying