Copper tools should have a timer when held rather than durability

I personally think it would be neat to have copper tools be given a separate breaking mechanic from standard tools. Make copper tools have a high base efficiency while keeping the minable blocks by them the same. However, instead of having durability based on number of blocks broken, have durability be based on how long the pick has been in use with it oxidizing over time before it finally breaks. This could potentially make copper tools the go to tool for strip mining or basic resource gathering without outright replacing the higher picks since it can't mine beyond iron.