Other options for turning around after 66B+KAB are holding G, 2 or both. you have to learn the timing though, because you don't really get the best visual cues and you have to start doing the first 236 as she turns around. As Senz suggests you can use a different post break combo too. Although it only works after breaking with some moves (I think most notably 6K), 4[A]A combos post break can be really strong too.
As for 4[A]A > 6BB whiff the main factors I can tell are opponent's character and their facing when the 4[A] hits(distance when hit can also play a role). Characters don't have the same hitbox sizes at all levels/facings and so two inter related things tend to change depending on who is being hit and where they are looking when they are hit. The first is that the opponent may get turned more or less by the 4[A] hit before the second A arrests their spin. This means that some characters, when hit from the front will be rotated a different number of degrees, some will have their side facing you, some their back etc.
To give an example how how the spin dynamic changes their facing, take Ω as a case in point. Unlike most characters, 4[A] hits her a frame later than it's first active hit frame when at close range (for most characters this only happens when far) because of that, she gets a frame less of "spin time" in the stun before the 2nd A hits her. Thus she is left closer to a forward facing than, say, Nightmare would being hit by 4[A]A at the same range. Of course their final facing is altered if you hit them while they were turning or something, because they start the spin from a different starting facing.
But even if you got Nightmare to spin just as little (say you hit the [4A] from far and he was close to a ring edge) NM has a notoriously small sideways hitbox. so even in the same orientation as Ω 6BB is less likely to hit him from the "same range."
Additionally, depending on the presence of a wall or ring edge, or how far away from opponent you were when 4[A] started, you may end the string closer or farther from the opponent too, which affects your chances of 6BB hitting
So it's likely best to think of, 4[A]A > 6BB as character specific. It isn't entirely, but to use it otherwise you're going to have to delve into testing the specific circumstances where the combo could work and then try to recreate those circumstances mid-match. Probably not worth the effort, but it's up to you.
can I do the 66B+K A B > 236236B combo? it's very difficult to execute, I always use 66B instead
