After a brief listening, using Amazon video and the regular Programm, there's no audible lack in the sync.
Tested with covering the BTR5 with my body and a 5 cm wall made of wood behind me additionally.
The distance between the transceiver and the BTR5 was at least ~ 5m.
Behind the wall and myself, there was a noticeable crackling, but not a consistant one.
But nonetheless, still impressed with the BTR5, or the pairing.
Maybe you'll get a different result depending on the transceiver.
Even the difference between the R28 and the BTR5 is just 0.1 sec, I guess.