It would be nice to have a button that opens the preview in a new tab/window.

Issues:

• On Safari (mobile and desktop), opening the preview in a new tab doesn't work. It always returns a Not Found error, and seems to be bypassing the service worker. Chrome and Firefox work fine, though interestingly I noticed if you hard (shift) reload, you see the same effect (but just for that load -- reloading again fixes it).

• The service worker URL won't be shareable. This could be confusing.