Interested to read lots of the horror stories and suggestions that other motorhomers would be mad. We've stopped at too many aires across France, Italy, slovenia etc etc and shared with caravans (and people in sleeping in self-converted cars). Anyone who would ask a caravan to move on would get a sharp response from me (what kind of person on holiday would actually give a @&##!). Fair enough if your caravan has 30 axles 4 awnings and portable tennis court but if your breaking up a journey in an aire then "hi nice to meet you, and good luck".
BTW that gassing story is as old as the hills. I once spoke to a Dr (in an aire) who said that's nonsense.