I think it makes sense to try using a combination of Grandma's Original molasses and brown sugar. That thought crossed my mind when I was at the supermarket recently, as I reported, and saw the light and brown sugars and wondered whether they were refined sugars. It was the "refined white sugar(s)" versus "refined sugar(s)" issue that led me to call MM.
Where we are missing useful information is in relation to the protocol for the frozen dough balls. I saw a video yesterday where the MM pizza maker mentioned placing the frozen dough balls into the cooler to let them defrost. However, he didn't say whether it was one day, two days, or maybe even three days--or maybe something different. From a fermentation standpoint, it makes a big difference whether you are using one, two or three days of defrost/fermentation. For example, if the fermentation time in the cooler is long, say, three days, the protease enzymes can attack the gluten structure and cause release of the water from its chemical bond. That could make the dough more extensible even though it might look like it is quite dense, and the dough might open up more easily even if it is cold. I'm guessing here. Also, knowing the defrost/fermentation protocol could also tell us more about the amount of yeast, and maybe other ingredients, one might start out with to fit the fermentation period. As we speculated before, maybe the defrost/fermentation period determines how sweet the finished crust is. Before I forget, I am going to pose some questions to GlennC. for when he visits the Decatur, GA MM store soon.
In your case, you might try using a fair amount of Grandma Original molasses with either light or brown sugar, with the goal being to end up with a final dough color that is close to the color of an MM dough. There is no easy mathematical way of determining how much of the two ingredients to use to achieve that objective. So, some experimentation will be required. Maybe something like 7% Grandma's Original molasses and about 4% brown sugar will work. You can also lower the nominal hydration by a percent if you think that is called for based on your recent observations at the DD MM location. You might skip the wheat germ this time also. I am thinking of making an MM clone dough ball and just watch it go over a cycle of two or three days after moving it from the freezer to my refrigerator compartment to see how it changes over the entire period.