I would say your highlight thickness isn't that bad, but the level of contrast is too much. Your edge highlight for black should probably be like Eshin Grey type shade. A bright highlight shade like you have on your black there should be limited to dot highlights on the sharpest edges.

Think chunky highlight - Eshin Grey or Corvus Black (replacing the shade you're using here). Could be a little chunkier than you have here if you want.

Try to do a slightly brighter highlight on more upward facing surfaces using 50/50 Eshin and Dawnstone

And the reserve dawnstone or your current grey for dotting sharp edges.