I don't know if this is already a feature because I can't find it, but the ability to make another PC's Chocobo non-targetable would be nice.
I had a problem during 5.2's MSQ where someone somehow managed to put their Chocobo directly on the quest giver, making it difficult to get my quest. I'm pretty sure it was unintentional because they stopped moving as soon as they got to the NPC so they didn't have time to adjust their position to make their Chocobo walk into the NPC. What's worse is we completed the quests in the same pace so whenever I went to the next quest giver, that player and their Chocobo would also be there and block my way. Every single time. It was actually kinda impressive how someone could perfectly and unintentionally grief another player without even trying.
The Keybind to make other players non-targetable and makes their names disappear didn't really help as I could still click on the Chocobo. My only choice was to try clicking the NPC from different angles which was already difficult because the NPC was flooded by tons of other players trying to get their quest. If that didn't work I could only wait until the player moved on.
I had to do positionals on a quest giver just because I couldn't click through another player's Chocobo. That's just nuts.