There are at least 3 quests for the Amalj'aa daily quests that require the use of a Cavalry Drake temporary mount in order to complete the quest objective. The beginning step of all of these quests has been to visit the Drake Whisperer in order to receive the temporary mount.

Since the quests are provided at random, it's entirely possible that multiple quests of these kind can be given to the player at once. However, as there are different Drake Whisperers placed for each quest, receiving the mount for one quest does not also qualify as receiving the mount for another, even though the mounts are identical and the quests themselves can be completed regardless of which Drake Whisperer was talked to first.

Thus, it seems like it would be more efficient to just have one Drake Whisperer in a single, static location and accepting a cavalry drake from it counts as progress for every temporary mount quest you have active.

This also applies to the Sylph daily quests, as I'm going to assume there are multiple quests that use the Gobbue temporary mount.