Knowing a roost spot is good information. I normally don't crowd them but do use that info to decide how to set up an ambush point. I normally just hunt turkey in the spring and since they often come out of the roost and go to a field early in the morning that info is good. Busting a flock in the fall and then calling them back is a good tactic that always works. If they bust out of the roost they normally will get back together on the way to where they were going to go.