Hi,

During my current playthrough (Lead, Titanium, Carbon, Silicon, K2 Spaced Out), I felt that something was off when I reached Fulgora because I was barely getting any processing units. In my mod combination they also cannot be crafted locally without importing rare metals.

After investigating the final scrap recipe, I think there may be an issue with the Space Age scrap-recycling probabilities when BZ Carbon or BZ Lead are enabled.
I saw a similar issue in this post: https://mods.factorio.com/mod/bzlead/discussion/6a43b17270662b6743075f24

In Factorio 2.1, shared_probability assigns an output to a range on one shared roll, while independent_probability adds a separate roll. When both are present, the probabilities effectively multiply.

Space Age gives processing units a shared probability of 2%. BZ Carbon sets the processing unit’s independent_probability to 3%, resulting in:
2% × 3% = 0.06%

Similarly, Space Age gives batteries a shared probability of 4%. BZ Lead sets
the battery’s independent_probability to 6%, resulting in:
4% × 6% = 0.24%

BZ Titanium adds titanium plate as an independent 2% result, which appears to work as intended:
Processing unit: 0.06%
Battery: 0.24%
Titanium plate: 2%

Is the multiplication of the existing Space Age probability by the BZ independent_probability intentional, or were the BZ values intended to represent the final 3% and 6% probabilities?

If the latter, I think the fix would be to replace/clear the existing shared-probability condition for those results when applying the BZ probability, rather than adding a second independent gate.