I cant think of any guaranteed BT 6k force techs...i know after a BT grab to 2P+k you can do PK and that has a option for a force tech but im not sure if its guaranteed tho
yea you're right the set up does depend on them not tech rolling, but there's a lot of possible damage options if it connects which is why I go for it sometimes
What you found is nice that it negates a wake up kick, but if they tech up, you can't delay the follow ups enough to surpass their invulnerability frames, leaving you forced to be at a disadvantage due to recovery from BT 6K.
I've been looking for a hard knock down to a BT 6K(6)K8 force tech option. But nothing I've found so far is guaranteed. I could show you some really fun vortex resets though.