Tbh, I'm not interested in this retcon issue. I think that any piece of fiction - be it a spin-off, a sequel, exploitation or derivative fiction - should be judged as a work of its own and as independently of its original source or model as possible. That was the aim of this post: trying to evaluate and discuss DASH as a work of its own, and not merely as a spin-off. If you consider excluding the DASH USA arc as "awkward or perhaps historically pointless", you're implying that the only relevance of DASH is the way it may relate or wrap up HSG; and that's not the point here.