Why not forget holding tanks and just use portable tanks?

I used to do that with gray water only back in my Trailer days. Left the tote IN the trailer when I upgraded to an "A".

Only for Gray Used a port-a-potty though so it had a "luggagle" tank as well

Never have I been in a park with a sign like the Florida one. but then I don't park in florida (For assorted reasons I will not talk about here).