(Barry, you should have posted to the FrankenFM thread that has turned into an OTA TV reception clinic)
Well, if we're going to get creative, then why not throw this proposal on the fire:
1. Operators of LPTVs on channel 6 can choose between having an equivalent powered FM on 87.7 MHz or operating a digital LPTV. You don't get both. (and truth be told, they don't want both.)
2. No new TV operations on channel 6.
3. 87.7 and 87.9 are opened up elsewhere for new radio applications.
The phrase "on the fire" is intentional. by the way. Here's why FrankenFMs won't happen: if they are allowed, then the clamor to open up 87.7 and 87.9 as above would start for certain. That's either a downside or an opportunity, depending on what side of the industry you're on.