Well. On vulcanus you can't directly produce legendary plates because fluid-only recipes don't support quality. I haven't gone through the articles maths properly yet, but I'd be interested to know if it's more efficient to have a full quality pipeline from miners through to end products or if it's better to start from vulcanus 'free' normal qual plates and build from there. I suspect vulcanus probably does win, but it'd be nice to be able to simulate that.

You only need to mine legendary coal and calcite. Then you can get most of the non-planet specific items from there.

legendary coal -> plastic - > low density structures.

Coal is the only solid ingredient needed in this whole chain. Then that can be recycled to make legendary copper and steel.

legendary calcite -> stone (lava to molten copper recipe) -> concrete

Then that concrete can be recycled to make legendary iron ore.

Generate a huge load of vulcanus iron plates with speed modules, then feed that into assembler/recycler chain of iron chests (all quality).

Or, if energy/space isn't of huge concern to you: a lot of foundries with quality, and just dump anything that's not legendary into the lava.

Pipes and underground pipes end up being better due to productivity bonus of the foundry.