So it seems like the intention is for <install> to require a manifest URL instead of a page URL containing the manifest like the Web Install API uses. Personally I would like the have the option for either in both APIs. For example I might want to install youtube.com. Obviously a URL like that isn't going to change anytime soon, so I could just put that URL in the HTML. Whereas with a manifest URL I would have to periodically fetch the HTML and parse it to check whether the manifest was still at the same place.