Ok I've done more labbing and I've found a few things about Sindel's HTB Vortex dragon showed.
The JIP HTB can only be done Low to Overhead.
JIK can hit overhead to low but requires wave dashing into F1xxScream wavedash into B23 F4/ender but JIK ruins juggle gravity and doesn't work the same as combos with JI1/2.
JIK HTB can't be looped the way JIP can to be a vortex so if you need 3 touches with Sindel to win. The first two have to be JIP, meaning you fuzzy low to overhead and it's not very hard, it's a 3 frame window. So much easier than MKX Summoner Quan.
To be clear I'm saying you can't JIP overhead to low HTB if you want the timing to break armor, prevent backdash, jump and D2 like Dragon showed.
JIK comes out and is active much lower and hits faster at same timing as the armor break but juggles different and doesn't get the long combo required for gaining back Charged Lao Hat mid combo.
So unless someone has a way to stuff all wakeup options with JIK and still juggle long enough to have charged Lao back I don't see what's so incredibly broke.
Omni-Man, Rain, Mileena and pretty much every character can loop HTB and time it to stuff wakeup options.
Even if they can't gain Lao hat back many have armor break moves to take turn back and do it again.
I know at least 3 characters can Vortex HTB because they have enough knockdown advantage with certain specials, strings or Ariel strings that allow them to get JIP exactly on wakeup and juggle long enough to get Lao hat back which is the same speed as regular hat
On top of this if I time JIK to hit first while covering all wakeup options, you have to do a early JIK that covers them but half the time only breaks the armor, doesn't get the combo with armor break:
I can do it earlier and combo but it only combos if it's actually a 2 frame HTB that would automatically block if they attempted to fuzzy instead of wakeup Armor.
It's incredibly dumb to have to try to get 3f HTB down into muscle memory then somehow adjust to 2F HTB setup.
Does anyone know to juggle off the Vortex HTB setup using JIK hitting first but also timing hat to hit exactly on wakeup frame one but doing a long enough combo that ends in F4 Lao hat setup that allows Charged Lao Hat to come back mid combo?
The only one I've seen Dragon do is JIP HTB hitting low first and that does allow you to loop but like I said it's easily fuzzyable.
If y'all can find a way to juggle longer from JIK and end with F4xxLao then this is very strong.
Maybe I'm just missing something or my brain is rotted but for whatever reason I can't get JIK first and juggle cuz the limitations on combo ability after JIK's, it prevents her from doing several BnBs that she can do with JIP