Starting on Frozeta, I am stuck at the very beginning trying to make copper plates. This does not seem feasible, as scrap seems to be the only ressource available, and those do not produce copper plates nor copper ore. Also, the steam recycler recipe requires copper plates so I cannot build one. Am I missing something?

This mod doesn't do any of the modded planet compatibility by itself, it only provides the interface for other mods to use it.
Sorry to say I can't help you, I have made the creator aware of this thread though.

Sorry I was not aware of that, and thank you for letting me know.

Frozeta has its own setting to toggle if you use Any Planet Start, otherwise it softlocks you.

That's weird, other mods can detect if APS is enabled and if it's set to their planet, so why that isn't automatic is baffling me.