maybe no gang is necessary, and instead of classical skiving, a wedge shaped tool that would create a bur and lift it up in one pass, kind of like a plow is turning earthIf they are making those for $50 material & tooling costs included, then it is probably a gang tool/stack of saw blades and spacers in a horizontal.
With or without numerical control.
Gang tool in a shaper?
Especially if it is a Klopp?
with fins this thin, material removing tools need to be extremely sharp, and copper sometimes won't cooperate even then, and can dull a tool quickly too, so I'd expect it to be a nightmare with gang tool setup
and if I had access to wire edm, I would certainly not waste time cutting fins with it, but probably try to make a comb style tool to scratch those fins in, or maybe form in very soft copper, but all this is nonsense really if someone is already making money making these at 20-25$/piece for them to retail at 50, and just cutting it doesn't do either, you need to plate it to prevent corrosion, that is another can of worms on something that has sharp corners...