I too monitor a multi-site networked system. I have chosen to set my TSYS objects to Multi-Site STAT and NOT setting the "Check all CCs" box. The effect of this setting is that the scanner will scan the first active CC it finds on the first pass, then it scans the second active CC it finds on the second pass, and so forth.
I also limit my TSYS objects to only 3 or 4 sites.
My thought - I'm very sensitive to the lenght of time it takes to make one "scan pass" through the scanner's memory. If I program 7 or 8 sites into a single TSYS, and 5 or 6 of them are within receiving range, I'm taking more than 10 second before I scan my conventional objects and other TSYS objects when set to STAT and "Check All CCs" checked. That's a long time to miss traffic on the other channels.
I never had good luck with ROAM either. I can receive 3 or 4 sites fairly well, but the signal strength is not consistent when mobile or even just moving around the house. You can easily move to a not-so-strong site, and you also miss traffic that may be carried only on the other sites.
Your preferences may differ from mine. If you're not scanning many conventional channels or other TSYS objects, this may not be a good fit for you.
Simulcast sites are no different from single-transmitter sites, from the point of view of the scanner. Simulcast is when multiple sites all broadcast on the same frequencies, so the CC frequency is the same across all sites. There is nothing to "ROAM" to (a second active CC) in a simulcast system. But the OP could program the Wake County simulcast site CC in addition to other neighboring sites into a single TSYS object and have the same experience.