Take a look at

• all the ores

• alchemistry

• AlmostUnified default config is also a good palce (unify.json)

• Recipes / Cycles for ore purification

• Recipes / Cycles for material -> parts -> material

  • Decide: Do we need separate ingot + ore sulfurs, or can we do with just one metal sulfur (e.g. ore -> 2x metal; ingot -> 1x metal, .. etc). Logically the latter would make more sense, but do we have dupe issues?
    • seems one sulfur alone is fine so we go with that

Ore -> ore sulfur recipe, then an ore sulfur -> ingot recipe with output x2 (and double the salt input)

• which salt to use?

• expensive recipe to convert strata salt to mineral salt

The fundamental question for early ore duplication is: Where do we duplicate (ore -> sulfur, or sulfur -> ingot), and which salt do we use?

Ingot salts are not great, as there's no source for them - generic "mineral" salts would be better

EDIT: so let's do 1 ore -> 2/3/4 sulfur, then 1 sulfur -> 1 ingot; using "mineral" salt.
This makes getting mineral salt (from ores!) a bottleneck to ore purifcation.