Were you missing something?

Yeah, the way the model flies when all 4 aileron throws are the same.

The roll rates aren't going to be different clockwise to counter clockwise since the inequality works the same both ways.

What does happen is that having all 4 ailerons throw the same gives 4 outer wings that reach stall AOA more nearly equal. And it also happens with the stock rigging that one of 4 will have a lot quicker stall. You could say that the bad setup creates washout on one of the pair on one side while creating even greater washin on one of the pair on the other side, while no washout or washin is created on the lower halves at all.

I've flown a couple of other ARF Skybolts other than mine. Mine shows me no real tendency to snap out of stuff unexpectedly. I got no idea if that's because I've got mine better balanced, or if I'm just more familiar with mine. But the others caught me by surprise and didn't seem as easy to fly accurately. I also didn't feel at all comfortable slowing those others on landing like I do with mine. Probably just familiarity, and respect for other peoples models. Who knows.

I first saw the problem when I was assembling my World Models Ultimate 40, and fixed it before I ever flew it. And fixed the Skybolt on assembly. So I've never flown and gotten used to a biplane with the screwed up aileron rigging. It would be really interesting to have gotten used to the screwed up rigging and fixed it and gotten to see how much effect the cleaner rigging gives. But not "really interesting" enough to screw up my excellent flying Skybolt.

There are lots of models flying around with too forward a CG for "safety's sake". And lots of other details that are known flaws. And people are perfectly happy with 'em. kewl.....