Haha, this coffee stuff is crazy. Actually, the more experience I get, the simpler it becomes, go figure. Here's my story...
I am glad this question came up. My updosing saga went like this. I had 5 lbs of a medium roasted blend. I had pulled darker blends from this roaster before but not this blend. I waited 7 days to pull. At 18:36 it had an acidity I didn't like (sour). So I went about getting rid of the acidity by fining up my grind and pulling the same ratio. A few shots later, I found bitter and lost acidy. I didn't like JUST bitter and so I coarsened up the grind until I found a balance. But I didn't like this blend's acidity. So the next day I messed with reducing the dose and playing with the grind. No luck. Still couldn't get the acidity to become a flavor I liked.
Then, the next morning, I looked at the roasters recs: 20:40, so I up-dosed my double basket, coarsening my grind to get the shot time between 30-36 sec. Boom! sour acidity gone. Completely. But the pull was a little long in time so I coarsened again. Now the acidity was a nice fruit flavor and subtle. I was like "wow updosing." Then at 10 days post roast, I froze the remaining 4 lbs and enjoyed the coffee for the following weeks.
I moved on to other blends and just came back to the one described above. I was like, "i wonder why that updosing thing worked?" I thought through the little I know about extraction and couldn't figure it out. I thought, "if increasing the dose and coarsening the grind reduces extraction, why would the sour go away?" I looked at my notes, and went to pulling the coffee at 7 days, in the updosed amount. Agrgggg! Sour! Why didn't the updose trick work???? Well, 3 days passed, the coffee hit 10 days post roast and the sour transformed to a nice subtle fruit flavor. Go figure.
So I thought my updosing did something to the flavor, but i never made sense to me. It turns out that really, the beans hit the right age for the acidity to mellow out. At least, that is what I think now