Basically just aquiring one of every aquirable (non-tall tale) chest in the game (probably also including variants like shipwrecked(barnacles)/ashen), obviously its not ideal because they are adding new chests constantly, but it would be cool nonetheless. The best part about this is the amount of game knowledge and execution that would be necessary to perform well. The routing could be very diverse as well with how many different aspects of the game you would need to explore each run. I will now resume my FishES% runs.

Just having them on the ship at the same time or also selling them? I personally think it would be a great speedrun category just hard to keep track of all the ones missing and alreeady obtained especially for the mods. They would also need to make a new section after every new chest added(But I personally would love to do that XD) and(Good luck with your FishES% runs)