Hello @independant-consultant – thanks a lot for the input. I usually put the crust on a pan then place that pan on a stone in center oven rack when par-baking the dough at 450 F for 5 minutes.
Per your comment, this makes me wonder if indeed the heat transfer between the stone to the pan and then the pan to the crust is limited in those 5 mins causing moisture to evaporate and not setting the crust structure enough..
400 F for 2 mins seems very low, it usually takes 6-8 minutes for me at 400F..but again that is using a pan. I will try using parchment paper on the stone instead and see if that improves end product.
Could the evaporation and dryness be taking place in the final bake by the customer / after freezing instead of the factors you mention in the par-bake process? I bake the product for 7 mins, 425 F or 400F, 10mins after taking out of the freezer.