I think there is documentation that when hops interact with yeast in suspension certain flavor compounds are created.
Yes thats the case as I understand it and the point of the first dry hop hitting the active yeast at the tail end of fermentation. I'm figuring that if I do not take advantage of that active yeast period I might as well have all yeast out of the way. Much like Morty has when he hits his second (and now clear) keg with dry hops.
Another way to take advantage of that active period would be to use a highly flocculant yeast a la Firestone Walker (WLP002, or similar). Most of that yeast has probably hit the bottom of the conical before they add that first dry hop charge with 0.5º plato left to go. But there may be enough yeast activity left to take advantage of the "new flavors created". I can't say for sure. Does that make sense?
I am also wondering if the "new flavors created" aren't significant enough to get excited about. There hasn't been anything convincing to me that double dry hopping matters except in terms of theory. Few people have been able to discern a difference.