I'm running create alongside a few other mods that also add metals, such as copper. I've already generated the world with ore worldgen from one of those mods so I've currently got two instances of copper ore, ingots, dust and nuggets.

It would be neat if registering of metal resource items could be disabled using config options on Create's side and that the same items from other mods could be used instead (using item tags). It would probably be useful if this could be configured per item in case some mod doesn't add all variants, e.g. Mystical World adds Copper Ore, Copper Ingot, Copper Dust and Copper Nugget, but does not add a Copper Plate or Sheet.

p.s. The new update looks amazing!
pps I can take a stab at it and plop a PR if this seems like a reasonable change

Thank you for your suggestion, I absolutely agree with you. If you feel comfortable with it, by all means go ahead and create a PR, otherwise we will start working on that shortly and most likely include it in some of the upcoming patches.

Removing items from the registry based on config is discouraged. Create's ore-gen is completely configurable and most of our recipes use forge tags instead of the create metals. What more can we do to play along with other mods better?

Thanks for your suggestion, it has been added to our public submission sheet.