Hypothesis
Here's what I suspect about the results.
First, as an aside, I'd love for the Quantum pack to fit in the main wash cup, but I'd also like a pony. Truthfully, the first wash/main wash segments on this machine are pretty identical, so it's kind of a six-to-one, half-dozen-to-the-other issue. It's not like a GE, where missing the main wash is a big deal due to its duration. Still, chlorinated gel is not a great peanut-butter fighter.
This test revealed something I secretly wondered about all along. The Roto-Rack was designed to eliminate dead spots in the top rack, and in that respect, it performs admirably. However, the jets are pretty aggressive on this unit (as in, canted at sharp angles). Washing performance isn't just about reaching the dishes with water--it's at least partially a factor of how much time the spray spends on the surface of the dishes. If you pass the wash arm too quickly over them--or spin the rack too quickly above--the water spends a very limited duration washing the dish, and the "scrubbing" effect achieved by a little bit of dwell is negated.
So why don't the Big Blue KitchenAids suffer this injustice, you ask? I suspect it has a lot to do with well-engineered pressure of the spray from the arm, and the sheer volume of water those machines could move. When I videorecorded one in slow-motion on my iPhone, the water sent upward from the arm was still falling back toward the sump as the next sweep of the arm went by. That's some serious water movement. The Roto-Rack won't come close.
Still, for daily dishes, we've gotten great results from the combination above--no rejects so far.
I guess we'll have to limit our imbibition of peanut butter, though.