There is a way to hit the 1,2,4,3 filler with Kazuya consistently on some combos without much execution required. For example after EWGF and during the lightning animation you mash fF+1,2,4,3 to get a micro dash, easy to do since EWGF recovers almost instantly on hit. There is no need to delay any of the hits this way. The first jab will whiff and the rest of the pre-tailspin combo will hit without any more dashing, connects into df1,4 and then you finish with df1,4 for the splat, then the usual run up into empty crouchdash, ws4 - df1,4 - 1+2 wall ender. It does 90 points of damage instead of the usual 84 if you just filled the first 3 hits with 3,1,4. On a CH df2 you can buffer an SSL then when Kazuya recovers you hit the f1,2,4,3 and if you got a small sidestep the df1,4 tailspin should connect, but this is very strict and IMO not worth attempting. On a CH b1+2 and f1+2 the combo hits without any adjustments but it wouldn't hurt to do the micro dash.
Off axis the first combo will not hit. If you are off-axis even slightly to your left, you will need to time a dash after the initial 3 fillers to land the rest of the combo, but this defeats the purpose of doing this combo in the first place because the timing of the dash into df1,4 after the 1,2,4,3 is kinda strict. Post "random dash electric" this combo will hit as well as when EWGF is used for block punishing. If you EWGF after sidestepping I'd say you need to make a habit of doing an easy staple instead of this one. I've tested this combo and it hits on Katarina and Xiayou. With Gigas you don't need the dash, doesn't land on bears obviously due to their short legs.
Kaz has a new back turn punish sequence: df1,2 - ws4 - 1+2. 69 dmg all guaranteed, crouch turn and standing turn into stand block won't escape it. Standing turn attempt after ws4 does happen, but the 1+2 still hits.
Devil Jin's db2 is actually -13 on block now and only +3 on hit. The tracking is also garbage now and doesn't track at all to his left, it tracks steps to his right but it can still be walked that way. If you walk left you can catch him in the back after a point blank db2 whiff.