You are misunderstanding the way this tactic works. With Chun-Li it is not a gamble, it is a 100% hit confirm. You do not hit any buttons until after Yun activates. Let me explain:
When you suspect Yun will activate, you do QCF motions such that a QCF is always buffered.
If Yun activates, wait until after the super freeze and then input D, DF and then drum kicks on DF.
So, if you’re using this tactic correctly, you are not taking any risk whatsoever. You don’t hit any buttons or even complete your super motion until after the Genei-Jin activation. You can do this from about a 3/4 screen away or closer. Some other characters can probably do this besides Chun, but I only do this with Chun.
Also, I believe Smoothcat is correct that Genei-Jin activation is -6. It might even be -5. -12 is way off, to whoever said that.
Actually there’s a perfect example of this in the new batch of Yun vs. Chun matches on Game 41.
since I’m a yun player I can tell you one trend I see in vids and players alike.
Yun will sometime activate after l.foward -> geneijin then try to l.foward again into shoulder. I think there’s a psychological element to this but just parry it and punish it to shit, it does not combo (as much as i wished it did)
If cr.mk hits, you can connect cr.lk->whatever after activating.
Ir also connects to cr forward it just need a really strict timing