I hear your point but f you haven’t tried it. You can’t respond. It doesn’t effect the balance. And I know what the vent hole is for. Try it then get back to me. I totally out climb all my buddy’s units.
I dry them out after each use
You can only know for sure by trying
Cut your foam to about a 1/2” lower than where your treads meets the side wall. Vent the rims. Fill with water amd hot glue the vent hole. Works amazing. Good stability and max unsprung weight