Historical hypothetical: if aluminum production had been discovered earlier/been easier to do, could aluminum coins have been a commodity currency? If so, where in value do you’d think they’d be?

Well, they’re light, the metal is useful, so those are pluses.

On the other hand, aluminum does corrode and it’s probably too useful as a commodity to work well as a currency – generally not good if people keep melting down the currency in order to use the metal for making stuff.