stand b, 2a spam and 6C almost guarantee you eating a 1/7th life combo (that result in a knockdown) every time you backdash in a ground string. dont rely on it heavily at all. its actually an ok anti-air, though.
if you need to make jin stop being predictable in your face, IB 360A/720. you should try to IB jins strings a lot anyway because its actually relatively easy and the reward for it is really high.
when jin does shit like instant jB, THATS a good time to backdash, he doesnt have a lot of options that will hit your backdash (none of his air attacks hit very horizontally or are active for too long, jD might hit on rare occassion he has to use ex fireball, pretty much). from there you can 2A as he lands, or just wait it out again, and avoid some of his pressure (so you dont take as much guard bar). you will need this precious guard bar or barrier gauge throughout most of the match.
a good thing to look for is if jin ends a string in jD, his options become a branch of unsafe. either wait (gives you initiative), dash cancel (hes not at frame advantage), or cancel into fireball (free sledge if you're looking for it) or ice car (unsafe unless he RCs and gets a free mixup). stand b is probably the second best time to guess in a string, if you IB either of the hits, 720, or you're making him jump/backdash/dp, which limits a lot of his choices.