I have to ask, although I agree a hard knock out punch will knock you out, how are you training that punch? When I train I focus on proper head movement, and strikes to setup my takedowns (its' a fight not a bjj match). So are you training to deal with trained strikers closing the distance to a clinch?
I personally never recommend the one punch one kill approach. I've been hit very hard with no effect, I've been grazed and knocked on my butt. It's not reliable. This is why the UFC calls it a punchers chance.
I made it quite clear that the requirement to succeed with a "simple" technique is superior awareness. Currently my awareness is good enough to deal with people on depressive drugs, like alcohol, possible a random untrained mugger. Is it good enough for a trained fighter? NO! I never said it was. I said O'Sensei's was, hence the overwhelming success Aikido had when it first spread around the world. I also stated the purpose of Budo is the development of awareness, and consistence hard mindful training cultivates awareness.
The physiological result of a blow to the side of the chin has been proven. Right now, if for some unknown reason I had to defend myself against a BJJer I am going for the choke aswell, because as I said before, in Yoseikan we learn to ground fight.