I have a dual Sena 5s that my wife and I use. Works well. However, my friend is purchasing dual Sena 5s units for him and his wife. I've seen information online that says these 4 units should be able to intercomm. It also implies that in the 5s manual. However, I just finished a CHAT with Sena support and they say only two units can intercomm. Anyone familiar with th 5s and connecting more than 1 unit?