I hope I'm not going to regret being honest with the park (although don't have much choice, this one is in a fairly a remote area and some of the people I'm dealing with are my part time neighbors who I talk to all the time). The state park personnel very much follow procedure ONLY - trying to argue anything I think would be similar to going into the DMV and trying to negotiate a lower fee for your auto registration.
I just talked to the guy who does the hot water treatment (very helpful). They have to completely fill the tank with hot water and whatever they use has a through-put of something like 4 gallons/sec or maybe .4 gallons per sec (didn't know exactly). At .4 gallons per sec, that is under 7 minutes to fill the tank. The hose also seems long enough.
However, the nozzle they use is too big for my existing setup. I've had my tank overflow into the bilge when the inspection hole was not completely closed and the back of the boat loaded. So I glued in a piece of PVC pipe to raise the overflow level. This is going to need to be removed and the guy I talked to said he thought his smallest diameter nozzle would require a 1.25 inch hole (not confirmed, he was not at the equipment to do an actual measurement). So, looks like this is the next mod I'm going to do to the boat - make the inspection hole have at least a 1.25 inch inside diameter. I probably will go over and visit them to actually measure the nozzle before I start drilling.
After all this hassle, I will be extremely reluctant to go to any lake which they consider suspect. I'm guessing it will hurt businesses at suspect lakes and I don't want to guess about how honest people will be about where they have been. Ill probably still do the once per year trip to Lake Powell and get a once per year hot tank wash.