Oh, thanks for pointing this out, I really mixed multi-process and WebExtensions and diminished main XUL problem (which I oversimplified for myself as "just pro

Oh, thanks for pointing this out, I really mixed multi-process and WebExtensions and diminished main XUL problem (which I oversimplified for myself as "just problem of settings pages to be rewritten to HTML" what is really wrong [0]). As I understand it WebExtension is inherently multi-process compatible so (to answer question below) the only extensions we know today will work next year from arewee10syet.com are those marked as "compatible-webextension". [0] Most of extensions I'm used to alters chrome visually or functionally: calls external applications, changes hotkeys, so almost none of them are XUL-free. But I still hope / believe Mozilla is not that insane and will achieve consensus keeping the most important features for extensions authors available in the end.