What you say above is essentially what Archtkd said below:I've read the book. I found it an interesting viewpoint, and it's certainly added a few new tactics and strategies to my SD arsenal. In my view, it sits quite comfortably with the KKW curriculum. I guess it just depends how you look at movements.
To my mind, Mr O'Neill wasn't suggesting anything so radically different to what we were already doing with our applications of poomsae in our classes. Just because it's called a block, doesn't mean that's all it has to be. For example, I've been using momtong bakkat makki as a brachial stun, and momtong an makki as a press to the rubbing point behind the elbow during an arm lock, for a long long time and have never been questioned by any master on it.
The application in the KKW textbook is one of many possible - the same textbook recommends exploration and selection of techniques and applications that work for the individual.
You make what you want to make of it. That's the beauty of Poomsae.
However, that does not negate what he said regarding the way that blocks are taught in Kukkiwon taekwondo:Of course one can use any part of their body to do anything they want, but it would be misleading for them to say they are applying or teaching a technique based on a Kukkiwon style form or technique that they misunderstood or rewrote. Were you taught to block with your forearm in Taekwondo or you learned it in other martial arts?
Serious taekwondoin with basic knowledge of Kukkiwon taekwondo know that the wrist (palmok) -- no more that 1 1/2 inches down from the wrist joint -- or the hand blade (sonnal) are the primary parts used in blocking in Taeguk poomsae, self defense and sparring (not the hand blade). Kukkiwon texts and all teachers I've known make specific warning about blocking with the forearm because it can be easily broken.
So yes, you can pull many more applications from arae makki than what is in the KKW textbook, but if you are using arae makki in a way that differs from how it is taught by the KKW, then while it may be a valid technique in the generic sense, it is not KKW.