after some messing around I believe I've found a consistent method, during Sieg CE animation if you buffer 33B BE and then do CE you should get 66A+B BE almost all the time
Okay, time to explain this since I've put you guys in limbo long enough.
Honestly, I was in the process of inputting 99b BE when the CE animation started up. I think I inputted 6 and A+B at the last second and this is what it produced. I can't seem to reproduce this btw.
And no, this doesn't produce a clean hit. I was just kidding haha.