non tradeable crafting currency?

Hello,
maybe we could give players trading currency that they can not trade with others? This way they could craft more without having more currency to buy things from the market.
Or maybe there should be a way to specialize based on how you prefer to acquire loot:
-just finding it -> gives you a way to target farm certain loot types
-crafting -> gives you significantly more crafting currency, but the additional currency is untradeable
-trading -> not sure yet, what would be a good benefit for that specialisation

I suggested a while ago that Gold should be the only trading currency for items between players. So many issues with loot are caused by balancing crafting material drops around the trade economy. It's super silly.

Gold would also have the advantage that sinks for it could be implemented quite easily. For example the gamble research boxes is a great gold sink that is already in the game. Taxation of Alva currency exchange and passive point reskill are others.