I tried that, too. There is no such method at this time that doesn't involve setting up something in between the browser and the editor to marshal between the browser's native messaging API [1] and the editor's desire to operate on text files. I don't think that's insane at all, but the complexity involved did exceed my frankly passing desire to get IAT back - I barely ever use it any more. It shouldn't take a reasonably experienced extension developer more than a day or so to implement, though, I would think.

[1] https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Na...