I don’t think blistering is necessarily good or bad, it’s a matter of preference. Some like it, some don’t.

sp is blistering a good sign? that means the gluten has been broken down, which we want, right?

Blistering is not really a chemical reaction, it is a mechanical action. It is gas escaping from weak points along the crust. Where the crust is weaker you see more blisters. Acid collecting on the crust in a sourdough or long-fermentation dough weakens it and causes blisters to form.

If you coat the crust with flour, that extra dusting reinforces the crust and prevents blistering. Whole wheat is generally weaker to begin with, so you may simply not see the blisters because less gas is held in by all that weak crust. Or it could have to do with your hydration level, acidity level, how much gluten development you had and other factors.