I haven't really followed the thread much past my last comment, so I'm speaking broadly here.
I, generally, try and give the most rounded answer I can in threads. It's why I don't necessarily state who wins when I give my take on a match. There's exception of course, like matches where debate rules won't really impact the outcome. Shadowcat vs a typical street martial artist, for example. Any application of her power renders her opponent useless, so there's no real "yeah, but how phased will she be?" issue.
These discussions aren't an exact science overall though, and it's not limited to PIS/CIS. Standard equipment is another area that gets tricky with certain characters, for example.
And the reaction times of non-speedsters is another problem. We do accept that they(streets, for example), aren't actually humans. In all honesty, they probably dodge lasers/bullets, or even explicitly lightspeed stuff, more often than speedsters pull off their "everyone is a statue" high end stuff. It forces us into a weird space, as streets could probably react fine to typical Flash--we dismiss those as PIS though, even if they occur more often than forum Flash showings. Then again, I also understand the need not to take that stuff too literally, as suddenly every martial artist becomes hypersonic-lightspeed in short bursts.
All that to say, I don't really have an answer. CIS can get weird, and I've found myself being harsher on the characters I like because of it tbh. I know their characters more intimately, so I know when they won't go for certain things. I got caught up in that in the Monet vs Grace Choi thread.