I don't know how it'd be done, but would it ever be possible to tie this to player progression rather than the boss defeated world keys?
As it is currently you can have players who join a server late or not as fast in getting to bosses able to teleport materials without clearing the bosses themselves if other players are further along.
ArgusMagnus[Mod Author]
It's unlikely I'm going to implement that, because the server cannot read player stats such as what bosses they defeated. So to implement this the mod would need to detect and track when a player defeats a boss by itself, which I'm not keen on doing for the time being.
LordPhil713
Yeah that's totally fair, I wasn't sure if something like whatever it is the world modifiers use for player specific raids could be employed for this but that's miles beyond my understanding.