( cut a lot of tresoe stuff that has been rehashed too many times...)
As I previously posted weeks ago, one of the criticisms of MultEQ XT by many audiophiles is the relatively low number of filter points. This has led some owners of very high-end stereo systems to observe that MultEQ XT adds a veil to the original balance of the sound or decreases transparency; an observation not shared by all I might add.

I've owned a Tact Audio M2150 class D amp for over 10 years and I've followed the Tact Audio User's Group threads on Yahoo's Groups for many years. I was considering a few years ago to get into Tact's RCS solution (Room Correction System). Tact's RCS supports 10K filter points over the 20KHz audio range, effectively giving it a 2Hz resolution. The Tact Audio digital room correction technology being designed for a single listener position and not being affordable to me at $10K back then ($15K now) for the multichannel TCS processor and about $5K for the two-channel RCS preamplifier prompted me to wait patiently for many years for other similar technologies to mature. The anecdote about Tact Audio's RCS, admittedly coming from Tact RCS users themselves, is that you have to put your head in a vise not to loose most of the correction effect. Audyssey's MultEQ, similarly to Lyngdorf Audio's RoomPerfect, Peter Lyngdorf being the co-founder of Tact Audio until he left about 6 years later to start Lyngdorf Audio, are digital room correction technologies that have been designed to allow room correction over a fairly wide listening area. I personally find this capability fairly important unless you always listen alone but on movies, how many people from a family really watch alone?
Now that MultEQ XT32 also has over 10K filter points, my anecdotal observations from the various reviews I've read on it lead me to believe, and I could be wrong, that it has been embraced much more widely by the audiophile community, even by some of the previous critics of XT.

These days, all A/V processors and receivers that offer some form of digital room correction feature programmable DSPs as opposed to fixed-function DSPs like a decade ago. Tact Audio has being doing it for over 10 years and Audyssey for almost 10 years. The A/V processors and receivers that run MultEQ XT and XT32 typically feature a pair of TI's higher-end Aureus digital audio processors that integrate not only a DSP core but also an ARM RISC processor core. Those DSPs have to first decode the licensed audio codecs (DD, Dolby TrueHD, DTS, DTS Master Audio, FLAC, etc.) and then apply digital room correction on top or whatever else feature the user may have chosen. Audyssey like Dolby or DTS provide their software code to the licensees that run it on the DSPs and those licensing manufacturers have to integrate that code with other features of their own like customs control software and if they choose an embedded OS like Linux or QNX. And in theory, you're correct, they should be able to install new software features so long as the processor has enough power and specially if the system has enough RAM and flash ROM to be able to install them in the first place.

I'll leave you with a review of XT32 on the Integra DHC-80.2 A/V processor from Kalman Rubinson of Stereophile. Kalman has tested many of these digital room correction systems over the years including the Tact RCS, Lyngdorf RoomPerfect, Anthem ARC, etc.

You can also read this recent review of the Integra DTR-80.3 A/V Receiver on Secrets of Home Theater and High Fidelity where the reviewer gives his impressions of XT32.