Seminole County recently completed their rebanding a couple of weeks ago, there are no more transmissions in the 851.XXXX and 860.XXXX frequency ranges on their TRS replaced with frequencies in the 854-856 MHz range, and the mutual aid frequencies are now in the 851-853 MHz range instead of 866-868 MHz range.
The only transmission I ever heard on the 700 MHz system was a weekly "FIN" test at about 10 AM each Friday. The new 700 MHz system appears to be a regionwide mutual aid trunked system as Martin, St. Lucie, and Orange counties has deployed identical systems as well. The new systems show up as sites of the Lake County TRS (although only in Site Trunking mode and not connected to the Lake County sites), which is being deployed as a regionwide trunked system for at least mutual aid purposes.