Interesting Bill, thanks for the answer. Putting heat aside, would you say younger or older doughs are more likely to brown off like that? Where is that point where sugar content is peaking?
This issue has been raised several times in the past and I have usually stayed out of it. Time of fermentation/proofing is very closely related to temperature. And this relationship is exceedingly complex with very small changes seemingly having a big impact. Metabolism rates for the various organisms in the culture are not linear nor are they in sync with each other.
Everyone here has the ability to precisely control the time, but temperature is far more problematic to control. A five degree temperature difference (say 60F vs. 65F) can be more important in the final flavor of the crust (and color) than an additional day of fermentation.
I'm not saying precise temperature control is necessary to create your best crust. But it is useful in understanding the process so that you can recognize when your dough has reached certain stages in the process.
Sorry for rambling on - just sipping some coffee before the pup and I head up to the forest.