I started a new game on Nauvis and noticed that the tiberium slurry that was being generated including a lot of scrap from Fulgura. Obviously as there are no recyclers this material can't be until you've visited Fulgura which is going to generate a lot of unusable resources.
At least for Vulcanis and Fulgura I believe those recipes should be locked to those planets. Ie if there's tiberium on vlucanus, then it has chance to generate calcite and titanium. I know that the core buildings (Foundry, Recycler) can only be built on those planets due to atmospheric conditions - could the recipe be locked to those locations?