Not sure if this belongs here, but it definitely affects quests.
Several times already I have wasted time trying to reach a location that needs flight.
Maybe I'm going at it the wrong way: when suddenly a lot of side quests pop up I try to do those first. Maybe I shouldn't? Maybe I should only focus on the main story until I'm ready to leave the map?

I think it would still be useful for quests that need flight to be marked (with a set of wings for instance).