I have my return spell set to The Lochs. I used it since I was going to finish a few sidequests there, but because there's a bunch of players camping Ixion and pushing the instance well past 300, I couldn't even return to an instance that only had a dozen or so people.

I used return and it only said 'The location is congested', even though two instances barely had anyone in it, AND it uses up the return spell, so I get no teleport and the cooldown happens for Return.

Return should prioritize doing to whatever instance has the fewest people, instead of just wasting your time and having you need to teleport to the map next to where you want to go, and then having to zone from there.