One idea I had that would be lore-friendly is the implementation of Lerasium alloys. Specifically, these could be more common dungeon loot that would add the metal power that the alloy is for. As an example, if you were to find a Lerasium-Copper nugget, ingesting it would make you a copper misting (without removing your existing metals). Perhaps some Lerasium alloys would even be specific to different loot tables, encouraging exploring. This could be a nice alternative to gaining new powers without immediately making a player a mistborn.
This seems like the kind of thing I would add but not necessarily enable by default. It is canon in the sense that we know this is what lerasium alloys would do, but since we never see them it might not fit into people doing book-based RPs
Requested by @RurouniTim on curseforge:
This seems like the kind of thing I would add but not necessarily enable by default. It is canon in the sense that we know this is what lerasium alloys would do, but since we never see them it might not fit into people doing book-based RPs