I really think that would be uber-cool! It would really get people invested in the system much quicker than if they have to re-engine their whole fleet to take full advantage of the system. I can visualize a USB port or similar to load the characteristics into the car for whatever you were running it with. I suspect people wouldn't mind paying a decent buck for that capability.
Since, as I understand it, the emitter is strictly sending data, the car actually wouldn't be that complicated. If the actual message format and protocol were available, I'd probably take a run at making one.
Guess that info wasn't released with the Legacy Info, but you think they might maybe?