A quick experiment today around boiling peanut butter in water. I doubled the amount of peanut butter to 56 g in 1 cup of water. During the boil it formed a complete emulsion, as far as I could tell there was no water, it was all very foam-like. After the boil, I transferred to a mason jar with total volume slightly more than 4 cups. It was initially uniformly cloudy white, but then settled into the 3 layers previously observed. The bottom layer was bigger than previously observed.
I used a baster to extract the middle layer (water) and tasted it - tasted like peanut butter, but not more so than previously.
There doesn't appear to be any major benefit of using double the amount of peanut butter, and the downside is that the greater amount of bottom sediment might mean less usable / uncloudy beer.