Can't make a correlation with swapping tanks, but about the only thing inside the coach with a gas connection is the cooktop/oven.
I have a version of this in a different brand I bought for checking some gas piping in my house some time ago. I've since started carrying it in the RV. There are several different brands in a wide price range. They do work on LP and are very sensitive; you can see for yourself with a Bic lighter. Much quicker than soap bubbles.
https://www.amazon.com/Detector-Port...32216528&psc=1