I recently did some calculations of Tier 3 drop rates for Boss Pokemon, and it got me thinking. Instead of changing the base game, why not modify the ItemFinder sidemod to allow players to add any item they choose (from Minecraft, Pixelmon, or otherwise) to the various chests in the game. Players would be able to customize what types of items spawn, in what number, and in which types of chests (dungeon, stronghold, nether stronghold, etc.).
If it's too difficult/time consuming to allow any item, perhaps simply allowing any Pixelmon item would be good. Then players could customize servers more to their liking. If this worked off of a file format similar to External NPCs and Structures, that would even allow players to share their ItemFinder files for ease of creation/customization.
Best,
Ayyavazi