I hope someone else can chime in here. I’m just saying this out of an abundance of caution.
The shims washers maybe an engineered alloy. You know, designed to not wear away against the metal of the clutch bell.
It’s awesome that you were able to make one, but it might not be a long term solution.
Again, I don’t know that for sure. Just a concern based on handling the shims (they look/feel like hard steel).