Well I have a CO/Smoke detector. Other side of the camper from the stove. (Yeah made that mistake ;-) ) I also do have a propane
detector. But to be honest I did that to make a beautiful young lady happy. I figure that is not a real issue.
One of the main reasons that I think that is not a real issue is that I check for leaks
as a part of my get-ready-to-roll process. Which also by the way includes checking the propane
operation for the frig and then turn that off and start it up and run it for a couple of days before I leave. But back to the leaks
I bleach and rinse my tanks (and plumbing) every trip unless they are really close together. I end with enough water in the potable tank to keep the pump full and turn it on til it stops running. Then I turn it off and wait a day. If it starts up when I turn it back on, there is a leak and I need to find it.
Now on point I also do something similar with my gas. I make sure I have everything turned off. I work enough gas to the hot water heater to make it easy to light
when I get to my destination. Then with everything turned of I turn on the stove for a minute or two and then off and vent that out. I then turn the gas on and light
the stove (with good ventilation) Once it is going good I turn it off. Then I turn off the gas valve. Then like 24 hours later I leave the gas off and light
the stove. I know that it will run just at 70 seconds without the tank on. If it runs less than this I have a leak. And then when I stop for the night I run the same test. So the leak has to occur in a unit newly parked and not moving for there to be a problem.
I suspect doing that is better protection than a detector.