Comment by tbrockman

Not to comment on the rest of article or the author's goals, but it's absolutely possible to use a content script (dynamically injected into the `main` world, as opposed to the default `isolated`, for example: https://github.com/tbrockman/browser-extension-for-opentelem...) and Proxy's (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...) to hook (most? if not all) Javascript being executed in the webpage transparently.

Which for some functionality would have been a bit more portable and involved less effort.