I'm not sure if you've already answered this, but what is your salt and yeast percentage for your dough for your 3-5 day cold fermentations, and do you use ADY/IDY/fresh yeast?
For my latest experiments, I've been doing a 48 hour cold fermentation and use about .45% ADY, 2% barley malt powder instead of sugar, 2% oil and 2% salt. The dough tastes great, but is very extensible when forming, and I do not get the oven spring on the crust like I would like. I question wheather I need more yeast or is the malt powder contributing to my issue. I do not use diastatic btw. I want to avoid having to make a sponge because I really like the ease and flavors of long, cold fermentation times.