While backing into our site at dusk, my wife asked " should I go back there and make sure you don't hit the only tree on the site? I said, no, huge site no way! Well guess what happened!!!:o Was able to straighten out the square tube in our tool room at work.
I would be somewhat leery of moisture coming out of the ground, I used to park my pickup truck on gravel and have a lot of rust issues underneath, wife's car is on the paved section, much less rusting underneath. When we purchased our new Class C, we had a concrete slab poured, I park the tires on plastic cutting boards during the season; in the winter I place the cutting boards on 2 X 10s to get the tires a bit higher off the slab.
I had a similar issue with a valve extended installed on my 2011 Sunseeker. I purchased a Pressure Pro tire sensor system and installed the sensors directly on the metal stems, no extenders used. I have been using these for 3 years now no problems, I set the tire pressure in the spring on my first trip and have not had to add air for the summer and fall. I do remove them in the winter.
We had the Big Foot Automatic system added by the factory when we purchased our 2011 Sunseeker 2650DS purchased from RV Direct in Albany NY, I believe it was a $2600.00 adder? Works great. I understand that you need to be careful when doing this manually not to twist the frame of the chassis?