I was going to mention this was online but forgot. >>'
The hitboxes don't make sense to me because we have highs, mids, and lows but there seem to be unmentioned hit levels in between those making them not so clear cut. Something like Kasumi's 66K is called a "mid" and hits people crouching but is so close to a high hit level it whiffs during several frames of Alpha's idle stance.
Don't worry about it too much since it is online. Still look up at what's going on so that you know what you can do in a better playing environment. The issues with some hitboxes are being fixed, this is for all characters though. Kasumi's 66K hitbox is concentrated in one area and does not extend much (vertically or horizontally) which is why she gets crushed at times by certain attacks. When it reaches the buffering of 66 and the animation are doing the most part. Alpha's idle stance is annoying but that is nothing you have to worry about in actual pay, no one is going to stand there and use that just to hopefully avoid one or two attacks.
Yeah some hitboxes do not make any sense in this game, 'tis why they are fixing some of them.
@iHajinShinobi
You couldn't have possibly tested it thoroughly because if you did, you would know that after 6P9 from Ayane is at -20 when Kasumi parries with her 3H, you are eating 66K for free while you are BT. If you hit button after it to attempt crushing her to prevent a mix up, good game. Unfortunately I am not a scrub (not saying you said that) but I can see what's going on the screen and that flip of her's is beyond telegraphed. After she keeps getting stunned for doing do it, you'll stop. Even if you tried her hajin roll to get away you run the risk of getting hit/thrown.
With 6P3, Kasumi picks up +1 and she can use 3H and still throw you so she doesn't have to switch up her parries for either defensive response. If you extend the roll then you put Kasumi at +18 which guarantees 66K while you are BT, if you short stop the roll you are in range of being thrown. You could hit a button, be my guess, but like I mentioned previously, it is not wise for characters to do that once she parries. You try to mix up your rolls, Kasumi can still move in on Ayane with no worries because she has frame advantage and she won't be crushed using the proper attacks after it.
All of that applies to the other string variants to the flip and hajin roll. Kasumi and Ryu are two different characters and their parries function differently as far as their effect after it. That's great she can stop him after he parries, but she is not doing that to Kasumi. Ayane still has to deal with her, you actually make it worse trying to avoid her, that flip is not happening, I am sorry. If you flip in the air against good players in the neutral game you will be getting taxed for that or at least you should. That flip is a parlor trick and nothing to rely on to get away from Kasumi's parry. The hajin roll route seems to be her best one if you feel the need to "escape". Still, it's just a parlor trick in this scenario.
You are better off just standing there if she parries those options because she is only at +4 and you don't run the risk of getting caught with something trying to run away from her.
If that is what you meant by saying what you said about her parries, excuse me for not having my cryptic reading skills up today lol. Yes, I am sure everyone here is aware that nothing guaranteed always come after her parries. The point I made, again, is that she does get frame advantage after her parries, and it is worth it rather than taking string delay mix up 24/7.