As I understood it previously, no. The RMC1 was touted as being very flexible with assigning channels. Whether they ever released the upgrade modules or not (one optional module was dedicated for extra subs!), I don't know. Added to Dirac’s bass management capabilities, I can’t imagine they would handcuff it that way, like an internal 3-way or 4-way splitter only being processed as a single channel as some lower end AVRs do.. Could be wrong, of course.
Regardless, this XMC2 seems like Emo’s answer to the ATI-Monolith HTP1, take their existing tech, downscale it by removing the expansion capabilities... (and what else, I wonder?)... and undercut by a grand.
At 3k, it becomes the first, most affordable processor with the level of functionality of so many assignable channels, more so than the flagship products from any of the major companies. Look at the options from Yamaha, Denon, Marantz, Anthem... you are still more limited in setup options with all of them pretty much than what is described for the ATI-built and EMO processors. (I still can't help but wonder if somebody left Emo for ATI or vice versa, considering the style of the inputs and assignability of the channels is so somilar... or perhaps its a function of Dirac being involved.)
Regardless, exceeding 2 subs on any of the more traditional brand's product requires a mdsp 2x4 hd unit to manage the extra subs properly, as none allow more than two via RCA output. (I use the 2x4 HD as an example, assuming you decide you want better control than just splitting the signal with a Y, or daisy-chaining some... which gives you no control over delay.)
As always, I may of course be misunderstanding something here... I'm only what, 6-8 months into really using the equipment I have... with almost no experience using any other brand. So yes, I'm still learning a lot about the intricacies of all the tech involved with just my Marantz.
More than anything, I think this approach of channel assignability and flexibility is wonderful. I feel somewhat locked into a box with the options Marantz gives. I can't think of a good reason why I can't run 5.2.6 natively, as an example. It can process Front and Rear Height, as well as Top Front and Top Back channels. But you can only choose two of those. The newest Denon Flagship allows 9.2.4 or 7.2.6 in the 13-channel AVR, along with last years Marantz AV8805... but the 7705 (both AVPs) still limits you to .4 Atmos.