I think you are asking for a tall order that only the RCS management would truely know, and they won't tell.
I believe that many talk groups were locked to a certain site or sites on the original RCS, and they probably found that put limits on users during a time of need for communication.
Since this one is newer, has better processing power, the ability for a radio to use any site is probably more likely.
I program my radios to what I think I want to monitor depending on where I am.