The info. I gathered from an internet search is that John moved to Melbourne, FL. Most of the pictures appear to be of his original Chicago layout - and the track plan is much larger than what was shown in the TM video; there's also photos I didn't recognize from the video.
I heard of the Bruce Chubb's model rr interface, maybe it was from the video. The internet photos show some of the circuitry - very complicated looking, yet from what I learned from the video the system was state of the art. As I think about the advantages of such a system, perhaps an operator can power a train more realistically, though I would think any speed control system would need to be deactivated.
C/MRI is primarily used for dispatching and signaling. allowing a model railroad to use CTC (centralized traffic control) that faithfully replicates prototype CTC to operate a railroad. That said, it could be used for related functions such as progressive cab control where the program automatically connects and disconnects blocks as the train proceeds along its route. C/MRI greatly simplifies wiring since modules can be placed close to the track or control panel as needed and everything is tied together with a four-wire shielded cable. In other words, no need to run wires from detection devices, switches, and signals back to the control panel. Everything is connected to the local module and the modules are tied together with the four-wire shielded cable.
Dr. Chubb is still active and helping with the group but the business end of C/MRI (JLC Enterprises) is now being very capably handled by Scott Schrader who is continuing to update, upgrade, expand and modernize the system. Two recent examples: he has put the manuals online for free download with real-time updates and additions, and he has brought out an improved grade crossing control card with expanded options for sounds both in sound files available and how they work in conjunction with the gates and signals.
C/MRI is widely used with DCC as the locomotive control system, so it seems using TMCC and DCS with it should be possible.