After a lot of development (and a lot more to come as well), I think the extension is genuinely a huge productivity boost. I’ve made it customizable, so you can remap keys, including even the regular Google Docs shortcuts.
I think I may make a write-up about the technical details, because this project was surprisingly hard to build. Thanks to Google’s proprietary rendering and editing engine, there is only one <canvas> element that stores the whole Google Doc. Unfortunately, the <canvas> doesn’t even store the actual text in your document [1]. This effectively means that there’s no easy way to parse HTML, which led me down a painful path of implementing Vim keybindings via simulating user key presses.
If you end up trying it out, let me know what you think, thanks -Viktor