[exikyut]

Well, every manifest.json contains the line

  "update_url": "https://clients2.google.com/service/update2/crx",

which I think is present so that enterprise-distributed internal extensions can point at an internal update system.

This being said, Chrome won't install .crx files from anywhere nowadays, only the official store. I'm not sure if this can be overridden - the way I think it works is that Chrome can be told to install extensions via group policy or some other admin-centric mechanism, and that once the extensions are installed this is when update_url comes into play.

[fauigerzigerk]

You can always load unpacked extensions in developer mode, but maybe it's not such a good idea to promote this option as a mass distribution mechanism for regular users.