John&Joey wrote:
Nope, looks like a winner to me.
If there is you do have a couple of other options. They sell a flange raiser for a home install, it may or may not work for an RV. Also, there always is an extra thick wax ring. Really don't know why that won't work other than vibrations maybe.
I looked at the flange extension kits and didn't see any more of a benefit than what I plan on doing, one of the box store reps said I did not need a rubber gasket in between the spacer and my flange. I said to him, what seals it then? He said you have to silicone it. Doesn't sound like a good way of doing things. On the wax ring, I think it would not work as you said because of the vibration.