A friend was a beta tester with a RV-4. Worked for him.
I feared hitting it with my Bogert tow bar as the tail light is so low. I went with the Skybeacon, I already had the Grimes Nav lights on the wingtips in the right spot for clearance.
For now, IF you are big on UAT "anonymous" mode, the beacons' host transponder must be pinged once per minute by ATC radar to be anonymous and it is not Anonymous until it sees a 1200 reply starting to actually leave your transponder in radar coverage.