Verdict:

Here are my findings as I go:(1) This is REALLY hard to do. I originally thought it depended on the character, but on further testing it doesn't. What you have to do is land the j1 low enough that you recover in time to do MB freeze within its hitstun.(2) If executed correctly, the ONLY way out is backdashing.- No attacks had a chance to start up - that goes for BA's d1, MB F/B3 - you're stuck in that stagger animation and can't do anything- Cannot jump, cannot duck- Oddly enough, the backdash would cut the stagger animation short and let him escapeThese findings are very interesting. They show us that any particular standing hitstates can have the following properties:- Link comboability (KF's hits with traits, Batman's trait)- Chain/buffer comboability (all strings starters, certain string enders that let you 2-in-1)- Immunity to throws- Can backdash (KF's standing 2, j1)- Can jump?- Can duck?- Juggles trustinme and any other KF regular I missed (sorry):Our task is clear. We need to catalogue all of KF's hits for the following properties. If any of then have more than 22 frames of hitstate (minus recovery if cancelled, where applicable), no immunity to throws, and cannot jump/duck/backdash, then a freeze is guaranteed. Otherwise, we can develop mixups based on what the opponent can and can't do.I'll start a separate thread for the catalogue.The tech above is viable. It is not guaranteed, but in certain matchups it creates a different 50/50 situation - MB freeze or slide, which forces a backdash/no backdash mixup. The slide is unpunishable, but the Freeze is. Altogether, useful against larger foes against whom the tech is consistent.But the important thing is that you showed us that hitstates have another property - can backdash y/n. Knowledge of this property could lead to much more tech in the future.