Timing is the biggest mystery, I agree! And gluten development degasses the dough and makes it a little bit harder to see how much expansion there has been – compared to a no knead recipe or using an aliquot jar. Also when in the bulk fermentation you do the gluten development can impact what the dough looks like when it’s ready for the next step.
I recommend getting a sense of timing through trial and error, and using the senses of sight, touch and hearing (crackles). I guess I’m mostly speaking about the bulk fermentation…my final proofing is fairly predictable. I don’t let the dough blow up all that much. Most of the recipes on the Breadtopia blog include a photo gallery at the end that shows “before and after” of the bulk fermentation and the final proof.
The more experience you develop, the more you can be fix mistakes by modifying the next step.
For example, I abandoned the dough in the video of the mixed method gluten development during the preshape. Forgot about it for over an hour and it spread far and wide.
But I shaped it and refrigerated it immediately, which kept it from over-proofing. (Usually I would give it 30-45 minutes at room temperature before refrigerating.)