I tried testing out this shippu vs ex srk business in fba-rr, and I couldn’t find a way to make ryu win. I made it so that ryu’s got an active frame at the same time that ken’s vulnerability starts back up.
This is ryu’s first active frame, which doesn’t hit because ken is invulnerable.
This is Ken’s first active frame.
I assume they don’t trade because supers have more priority than special moves. It also looks like supers ignore invulnerability by being able to hit pushboxes.
It’s also worth mentioning that the fba-rr script that draws hitboxes lags behind a frame, which is why it looks like ryu is getting hit at the same time he has an active frame.