The main thing is that the extension would still have to be able to run its JS on any page to be able to show the interactive sidebar. Not sure there is a way a

The main thing is that the extension would still have to be able to run its JS on any page to be able to show the interactive sidebar. Not sure there is a way around that, unless chrome decides to implement the sidebar api that firefox has (https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/user_interface/Sidebars https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Web...), then the sidebar code doesn't have to run in the same context as the page.