Well, the RMC-1 a 16 channel processor and the 13.3 chipset used is capable of up to a limit of 13 satellites and 3 subwoofer channels. Apparently, it cannot do 15.1 or 11.4. It's not Emotiva's choice. I am guessing sooner or later this will change, but for now, that's it. I'll take it!
BTW, if you "get rid" of one subwoofer channel , you still would be an output short for a pair of extra satellites (Wide or Height), don't you? And the kind of people who are going to use 4 subwoofers are surely technically and financially capable of inserting a miniDSP or something similar to sum a pair of subs to one output, no?
The picture of the rear of the RMC-1 clearly shows WIDTH hence 9.3.4 will surely be a possibility. Makes more sense than 7.3.6 IMO.
My home theatre would be perfect with 9.3.6 (adding Front Height @ 22.5° vertical above my screen) but hey! I'll take it anyway!