What the heck is Ergo supposed to stand for?
It doesn't need to. It gives me an OA with my off-hand, which I convert to twin strike. Twin strike lets me attack with both my main hand and my off hand, and it does not say that I cannot attack with my main hand if I was making it with my off hand. Attacking with my main hand again triggers 2-weapon flurry. And you then loop back to the first step.
Ergo, Twin Weapon Flurry does not explicitly permit you to use the main-weapon as accessory for any OAs. Ergo it does not, ergo no exception exists saying you can. Ergo Twin Strike cannot be used.
It doesn't need to. It gives me an OA with my off-hand, which I convert to twin strike. Twin strike lets me attack with both my main hand and my off hand, and it does not say that I cannot attack with my main hand if I was making it with my off hand. Attacking with my main hand again triggers 2-weapon flurry. And you then loop back to the first step.