The wire mesh valve extenders are best due to friction against the wheel. These can only be installed on steel valve stems also. Some wheels may have a cheap automotive rubber stem, these will not support the stress of adding the extender onto. An RV shop may have added the extenders without making sure the valve stems were the stronger metal ones. Most RV shops don't do tire work so they might have overlooked that detail? Extenders must be tightened gently with a plyers also, hand tightening is not enough.
I would also recommend buying a good quality 12 volt compressor to carry along with you. Northern Tool has one for about $80. bucks that connects to a battery, either RV or truck. I don't like the ones that plug into the cig lighter. Far to much current draw to inflate a high pressure tire. Likely to blow a fuse and leave you with no help at all.
Tubeless tires seem to loose air over time and always need to be inflated.
Good luck and happy motoring.