Easy mechanical solution.
Split the fine mats into a “crafter’s loot table”. This table only gets added to the base table if the killer’s crafting level is high enough to use the drop. Additionally, if your current crafting tier is the same as the drops, there’s a static bonus to the table.
Allow MF to effect this table.
This way, crafters who are self-crafting should mostly be able to make their gear, and may need to farm or mdk a little extra to keep pace. Crafters going for full discovery can slap on some Pillager/Traveler/Explorer gear and farm.
Legitimate crafters will spend much less time farming mats, non-crafters can’t farm as efficiently, and real-crafters wont bump into anti-farming code.
Balance the increased ability for crafters to gain mats by nerfing the crap out of xp given to your main xp bar. No more leveling professions by crafting, only crafting levels crafting. Boom, crafter’s have a market to sell to non-crafters, and order is restored.