Yeah, it really should be more explicitly stated that not all verifiable moves will be done the same way. I only recently noticed how much more different the hit sounds, including simply swinging sounds, make a difference.
Chun’s low forward sound is so smooth and quick that sometimes it works like music, where you just know this note goes here and then you get your cue for the hit confirm. While Ken’s low forward is a lot less smooth if you do it just statically and so must be used in that musical sense I mentioned earlier for one to truly benefit.( Then again, Chun’s hit confirm is so long that the best way to do it would be visual )
As just a bare-bones tool you whip out when you need to be absolutely sure not to waste any meter it will become predictable.
[ tl;drdon’t do all hit confirms/verifiable moves the same way/timing. All have different sounds to aid in application. ]
As for about whether or not cr mk is confirmable. It is. But like I said, even that, won’t be done the same way every time. This is why I disagree with the use of training mode block dummy as the go to method, especially considering that most people over here in the states are playing side by side and so the decision to block will never be a difficult one to make when you can hear that they’re pressing buttons. It’s more a matter of “finesse” or some sort of subtle agility and not really about dexterity.
An example of this would be Ken low short/ low forward vs another Ken doing the same.
The Ken on offense would keep a good rhythm going with the shorts and leave enough room for doubt so that he can also use the low forward. Well, one way to beat that as the defending Ken would be to walk forward and ready a low parry.
As cavalier as it is, it is the best option there besides “omg block and 2 frame reversal super” but there is another way to win. Using regular attacks, we don’t yet know when/where we can fit snuggly between those two attacks.
Two shorts leave me in full block stun, low short to low forward leaves a lot of space but not enough that I’d want to stop blocking, …and for no real reason let’s say we’re trying to keep the game on the ground. That means I’m not going to just jump in ( though you should 
LO )
Two shorts is out. Lk to mk is a good place to start. Low forward to low forward is real difficult anyway, unless you just stick to the basic low forward blocked->parry follow up and can be content with that, you’ll be using it to bait action instead of use it as a tool for actual hitting. Think rattlesnake rattle. See how his toe does that thing when he extends his leg and foot forward? I think I made a funny.
Okay, lk to mk. Lk will be a basic poke in this case. It is used to get the opponent to stop and block low or keep them in block stun. I think this may still apply if it hits. After that, they may be inclined to blocking quickly and then finding something to do or parrying quickly and then following up because you were using a quick short. If they indeed take to the situation that way then a low forward follow up could possibly hit and create a situation for verification. The situation prior to the low forward is padded and so you’ll have a decent grip on the stick compared to if you had parried the first attack. What I mean by padded is that the event that led up to this situation was one that gives you advantage, thus allows you to let go of some stress. ( Personally I go to neutral in these kinds of situations or use them to buffer ) Since you put them into block stun with your short , you go into your next attack padded with plus frames. This allowed you start this next event in the chain with some extra leniency in place because your attack will inevitably go before his if you don’t fall behind in the waving and meter whiffing games and because if you decide to go low forward after this you can use the extra padded frames in the beginning of your attack to start buffering for a super, so that when your low forward reaches the opponent the only thing stopping you from pressing that button to finish that super motion is the sound of a block.
There are even some motions that can be split by pressing the button or tapping and holding a direction + button press. I do this with Ken when I want to buffer for a super/uppercut but don’t want to leave it as just a low forward. This way, when I have been blocked, I can press forward and punch to get a fireball. And a late one to boot, so it’s safer. Or if it hits, I just press the punch/kick or if I didn’t expect it to hit, any button really.
Another way this could have gone down would be that after the short, the low forward ken waits a bit and then marks a line to himself about how close he’ll let this other guy get before he lets low forward rip. If one does choose to go this route, the other Ken has the option to use the waiting frames the low forward ken is using to take a step then standing strong so that he can stuff the low forward and link the verifiable standing strong.
I know it was lengthy but I hope that helped. Lemme read back and see if there’s enough for a tl;dr. No there isn’t.
tl;dr
low mk hit confirmable, all hit confirms are different, not just sounds or just length of time or just cancel windows.
Ken meta example:
[ Ken1-> low short, ken2 -> block low ]
a[ ken1->low forward>super, ken2 walk toward>low parry ]
a.[ ken1->wait>low forward>super/uppercut, ken2-> walk forward>low parry>follow up/get hit ]
a.[ ken1->wait>low forward>super/uppercut, ken2-> walk forward>stand strong>super ] // you could also parry low then standing strong but that’s for later
a.[ ken1->wait>low forward>fireball, ken2-> walk forward>low parry>follow up/get hit by fireball/block fireball ]
Now this is loosely related but…the blocked version of this is very interesting as well because the delayed fireball either gets swallowed up by the super because you did it too slow or is let out late enough that it hits the super out after the first hit. There is an instance of the situation that involves the blocked low forward ken cancelling to fireball and the blocking ken to reversal super and it turns out that the fireball ken did it just a tad bit too late or the supering ken did it at frame 1 because the super ends up going through the fireball.
LO )