> that this is an implementation detail which is not really related to the format. In this case, a polyglot zip/html file could also interrupt page loading via a window.stop() call...However, I admit that I haven't implemented this mechanism yet.
Well, yes. That's why we created Gwtar and I didn't just use SingleFileZ. We would have preferred to not go to all this trouble and use someone else's maintained tool, but if it's not implemented, then I can't use it.
(Also, if it had been obvious to you how to do this window.stop+range-request trick beforehand, and you just hadn't gotten around to implementing it, it would have been nice if you had written it up somewhere more prominent; I was unable to find any prior art or discussion.)