No gas to cook top

Finally talked to a very knowledgeable engineer at Marshall regulators (which was not the initial contact, had to ask to be transferred for reasons that quickly became obvious). Going to install a Marshall regulator at the tanks. He acknowledges that ambient air pressure does affect the regulators. And insufficient WC may prevent the stove regulator from opening due to decreased atmospheric pressure above 4500 feet elevation. He sees nothing wrong with bumping up the WC setting on the main regulator by 1/2" or so. The only problem will be if too much increase is necessary to get gas flow at the stove, the appliance flames will be poor due to too much gas and insufficient oxygen at that altitude — it's a balancing act. We'll see. He reports, too, that the Marshall 253HP and 253L will both work just fine in an RV application. Both produce 11 WC output. But final installation should be tested and set with stove burners, etc. running.