In my experience I have seen little to no horn communications, especially in passing/meeting situations, and I have been operating boat more years than I like to admit.
Heck, there is rarely any horn signals being used when guys are out in the fog!
My opinion, (and
only an opinion) if it is obvious what the other boat is doing (staying to the right side of the channel, etc) then belay the horn signals. Not that it is proper, but it will save you some frustration.