I'm with Ard. The fish (winter and summer) that I hook almost always do the dirty work themselves. I present the fly, they hook up.
But like everybody else, the hangdown is a tough one. Based on personal winter fish experience and interpretation, hangdown fish tend to be hooked in the nose (when hooked) and generally lost quickly, even the few times I got a fish to say hello after I slowly lifted and dropped the fly that was hanging below me. On about 1/2 the time, those hangdown fish were briefly stuck, then they vamoosed, pronto. Half the time they weren't stuck at all. A very small percentage of the time they stayed pinned and were hooked right in the snout.
With summer fish my experience is more limited. Those very few hangdown fish have been very "plucky," picking the fly up gently and releasing quickly. Not one hookup.
Tough nuts, those guys who introduce themselves while right below you. Let us know if you figure out how to crack them.