I totally agree about two beat kick being interpreted as a reduced fly kick, and all your other comments, especially about Shinji and his stroke. All the bandwidth about the idiosyncrasies of his stroke on this forum, and not one about the most fundamental part of that stroke.
Hopefully there is no danger of a mutant stroke, as the challenge as you rightly state is the subtle release of tension within the torso at the right time. Perhaps not to the extent where fishtailing occurs...but in Lucs case, in that chop, I think he can be forgiven! :-)