Thanks! I enjoy my innocence and don't want just anyone to take it from me.
Optimal and speed may be the name of the game now; but, it doesn't need to be in the future. It's all in how you design the reward structure.
If you are reward exp and gil for completing the instance, players will want to complete the duty in the least amount of time.
However, if you place rewards throughout the instance, with the addition of obstacles in the party's ways, and offer no duty completion bonus, then players will be more inclined to search throughout the dungeon.