I have friends and relatives who have park models, both in little communities of them. They build them into the site in such a way that you would not know the porches are not attached or the carports either. They have residential A/C units and look just like a mini mobile home.
One of them is in Arizona and is a year round residence. The other is Here in Eastern Washington on a lake in the desert and is primarily a vacation home but still a fairly permanent installation. I would not classify any of these as an RV. I Think they probably should have their own set of rules, not lumped in with mobile homes or RVs. Mobile homes are not usually mobile either other than the day they are first purchased. This would seem to be the same situation.