What are the signs that bulk fermentation has gone long enough
I have read about the benefits of retarding dough during bulk fermentation in order to prolong that fermentation and thereby enhance flavor, about the signs of over fermentation, and about how longer fermentation is generally better for flavor than shorter or rushed fermentation. I haven't been able to find any clearly stated way to determine when the bulk fermentation has peaked though. For sourdough, how can I tell that I better get busy because my dough will soon be heading over the line? Is it as simple as waiting for the dough to (roughly) double in volume?
How are these signs impacted by the composition of the dough? Are the signs the same for (all other things being equal) a 30% rye/70% white AP dough as they are for a 100% white AP or a 100% whole wheat dough, and if not, how are they different?