tdrace
Having made the outward journey on an A380, light years away in comfort, I can tell you that the fares charged on the two BA flights per day, one of each type, were identical.
And the A380 is certified for 11-across 3-5-3. Nobody however has done it. Same bean counters presumably. And if you would care to look at the marketing material the two manufacturers produce, you will see that the A380 sales team proposed as normal the original A380 seat configuration, while Boeing moved on very rapidly to making the 9-across their standard offering for seat-mile cost examples. And it was Boeing, not the operator, who designed that cabin lining bulge around and behind the door, extending to squish the ears of the passengers sat in the first seat row. I think you will find that was not a customer-selected option.