No gas to cook top

Bought a Yellow Jacket manometer – not expensive. With stove burners and water heater running it showed a fat 11.5. Marshall engineer said even 12 qwould be ok but to watch for poor flame at high altitude (due to lower oxygen). He also emphasized that all regulators are affected by altitude pressure, My instinct would be to set the main regulator up a bit for higher altitudes due to lower pressure. Kids have a new Escape trailer and others owners have reported that the OE regulators supplied are all over the place. So the easy and inexpensive thing to do was replace the regulator with a highly regarded one.