On tablet - create new thread, enter mesage, swipe down out of habit, message is lost
FYI I tried on a desktop assuming that swipe-down was the same as reload page. It also lost the message. I tested page reload on phpbb and it also lost the message. I conclude that it is not customary to protect against page reload during forum message entry.

However, I think swipe-down on a tablet is an easily acquired habit and I'd appreciate protection against it. Especially in preview mode since preview and swipe-down are semantically the same "let's see the most recent."