If you’re open to ideas.
I think adding another tier chest spawns would increase points of interest, encourage map exploration, and give some more map based quests.
You could add a couple of spots on the map (i.e. the top of the North Tower) to have a next up tier chest with greater chances of loot. You could even gatekeep/lock these chests by clearing all mobs in the area, or something similar.
Maybe even randomize the chests a bit too, like a 50% spawn rate.

