[blitmap]

I mean you could absolutely inspect the source for the page, but these things could be modified at runtime by JS, right?

I'm talking about the meta tags. It would be neat to have a toggle on the tab for isolating the content of the page from the network.

[ijpsud]

You'd have to restrict localstorage and stuff like that too, else they could save data and then send it when they regain network access.

If you have a use-case, or some ideas, there's Chrome bug page for "offline-only PWAs": https://bugs.chromium.org/p/chromium/issues/detail?id=995236