I have practiced opening ours, just to make sure it works and so I know how in case of a fire. If I cannot open it then I'm going through it. We are about 5-6' off the ground and I'd rather break something than burn to death.
Our propane alarm went off two years ago, we were outside, several of my neighbors were at my RV and inside ensuring everyone was out, shutting off the gas and opening windows before I knew what was even happening. This was our second trip out in an RV and I was amazed at how quickly everyone reacted. It's a great feeling knowing there are fellow rvers there to help.