Copper Progression

Copper tools have a hard time fitting into progression, especially the pickaxe. How you could make the tool more versatile is by allowing the copper pickaxe to mine any ore in the stone layer. The desirable ores in the early game (coal, copper, iron) generate above deepslate level while the more late game ones less frequently (diamonds, gold, redstone). This would also follow the implied progression i.e. being deepslate is a tougher rock and requires better equipment (iron). It would give the copper pickaxe more uses for mining ores like emerald and would help newer players understand progression as copper generates in more frequent amount therefore it must be lower level tool. This idea would also require stone tools be rebalanced so they couldn't mine deepslate coal and iron ore however this shouldn't impact gameplay very much if copper is given this increased functionality.