Great investigation.

As I listen to the details a methaphor comes to mind.

Imagine explaining why one lump of uranium blew up, while another one did not.

The explanations would be about how this nucleus split in one lump leading to yet others ... and explanation trillions of steps long. And the other lump had a different story with fewer splits.

But the real explanation does not lie in the details of those splits. One lump had sufficient mass to trigger chains while the other did not.

it seems Europe's innovations spawned others for a mariad of reasons, but overall the probability of one split leading to two was just higher in Europe.

I suspect it may be the number of communicating scientist-ish people. and the printing press helps explain this, but in another way, the printing press itself is just another split that needs to be explained.

maybe like guns, germs and steel proposes it is basic geography that put europe out in front?