That certainly is the correct way to do it. The coach will be more stable and perhaps a bit safer if all of the tires are touching the ground. They provide all of the lateral stability to prevent side loads from being applied to jacks that are no doubt far extended if the wheels are off the ground. That said I don’t get fuzzed up if one or both front wheels are off the ground a bit. I won’t let the rears be off the ground because that is where the parking brake and the transmission locked wheels are. Once they are off the ground you lose all kinds of stability!
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