You're not telling anyone exactly why you think 66KK4 should jail, other than wanting an easily abusive tool for approach.
I tell everyone this that wants to play this character; if you HAVE to rely on 66KK4 as your primary approach, then you're going to get beat easily, and it's a fact. Everyone that fights this character expects this string on approach and seasoned players are ready to punish it. It is not meant for approach nor is it Ayane's best approach tool.
(only reason why I've done in high level play was for two reasons; to see how well someone reacts to it, and to further prove how terrible it is because majority pick things up from me and my play). The more you rely on this tool this way, the more you'll struggle.
It is a pressure tool (in threshold and on block conditioning). You can use it to close distance but it's use is small and sparingly for that because people expect it.
I tell you this all the time and you keep refusing otherwise, lol.