I would imagine it could be stable enough to hang inverted like this for several seconds before it fell off to one side or the other. Most planes hover somewhat easier as the CG is moved back. Looking at this as a pusher, the CG is waaaaaaay back. I may try it with mine before the night is over. I think I'll hang mine from a string so when it does fall out, it won't cause any damage.
Later,,,basmntdweller