I looked up MoCA 2.0 and it looks like the 16 node limit is intact, it just increases the speed.
If disabling DHCP doesn't stop them participating, I guess I was misunderstanding how MoCA works and it is capable of operating at a low layer below IP (maybe comparable to something like token ring?) Perhaps I should be referring to a collection of MoCA nodes as a segment, not a network. Bridging two segments together via IP could allow exceeding the 16 node limit since they'd be in two independent segments of coax which is where the 16 node limit applies. The multiple segments bridged together would make a network, but how the software on the receivers deals with that would be luck of the draw. Nothing would stop some crazy rich person from having 200 DECA nodes on 20 different segments all in the same IP subnet talking to each other. Directv probably doesn't want to support that sort of thing because the audience for >16 DECA nodes talking to each other would be small, and they don't want techs who may know nothing about home networking trying to troubleshoot someone's home network.
As for the DVRs on commercial accounts, I'm not a private viewing account and I was told that I could have DVRs on my account and be able to record and play back anything except PPV stuff which isn't a concern for me. Just that currently it could only be played back on the same DVR on which it is recorded, and that Genie wasn't yet available (but would be "very soon")
I may have been given bad information. Is there any way I can call in and talk to a higher level rep than the one you get shuffled to when you call the commercial account support number? I'm sure someone working for Solid Signal knows this a lot better than some random rep. Although I have to admit I'm confused when they tell me I can't get a Genie on a commercial account but Solid Signal sells a DIRECTV HR34 RVU for Whole Home HD-DVR (HR34) FOR COMMERCIAL USE ONLY. I'd really like to be able to talk to a higher level Directv rep to make sure I'm getting accurate information. I'd be really annoyed if down the road they sell me 3 Genies but then won't activate them because they say I can't use them for public viewing. Or worse, they let me do it and then come after me later telling me I'm violating the ToS.