I'm afraid that I don't agree with using a breakaway halter for anything but as a turnout halter (and I don't like haltering a horse in a turnout).
I use a rope halter when I tie my horse to a trailer or for any reason. A horse that learns it can break a halter many times becomes a habitual at it. I want my horse tied so that it can't get free unless I undo it. For that reason I try not to leave my horses alone and I always use a slip knot for fast uniting with me still having control. (There are, of course, times that they are alone such as on overnight rides, or when we stop for a lunch break, etc.)