I like how you ended that. Because most of the time the pak sau isn't much usable, because nobody throws inline punches on the street. Its always offset, or a hook, which in theory is easy to block, but reality its a bit harder.
We are 100% firing from the elbow at this point. Only, because this is a drill we teach new students on their 1st day or 2. But, I agree with you later on.