I don't necessarily agree with your comments on Mooresville and the County. I feel like Mooresville tries to go with the cutting edge of things, but maybe I'm impartial.
I would rather say that the County doesn't want to spend the money instead of that they don't have it. As I meant to elude to in my earlier comments, some of the County's prior leadership was dead set against anything Mooresville wanted. You might say there were some serious conflict and ego issues.
Nevertheless, I can't say that I've heard any serious conversation on adding a VIPER tower site. I do know they have been working on adding frequency capacity at some of the existing sites, but haven't heard how far they are in their progress. I also have heard that some VFD's (Central is one) are having issues with Fox Mountain (Central's district is pretty much in the shadow of that site).
I think you hit it on the nail for Sheriff that they will have to wait for a full switch until they get all their stock switched to 7/800 mhz capable. Until then, we have to monitor UHF & 800.