I'd suggest less hip turning and more turning from the waist with the feet remaining stable. Power will then transfer in a different path. Rotating on the heels is not something I would ever be doing in any type of training- for any reason.
Dan, interesting post. I'm assuming you're talking about the first one? If so, three comments. First: again I'm trying to actually do the solo exercise with resistance. I need to work at it more, as I mentioned to Mark, with most folks I can basically just do twisted mabu, but Jeremy is really solid. Second, the more applied version of what I demonstrated there (the one that Neil likes a lot better) is much more in line with what you recommend. The waist drives the cross in a pure horizontal plane until uke is compressed then we add a weight drop to effect the throw. Third: the heel rotation is from our Yanagi Ryu influence, so take it up with Don.
Thanks very much for the comments!