I made a small framework to build browser extensions with Typescript and React: "VFE" (I have no creativity).
It's more focused on hacking/modding things, this is the reason why it supports 'natively' page script(a script that runs directly on the web page allowing you to do hooks and whatever you want on the page).
Currently it supports cross browser build(chrome/firefox), automatic extension reload on file changes and allows you to customize webpack configuration(add plugins and so on).
The current goal is to make some API to facilitate request rewriting and communication between the scripts if you don't want to put all the logic on only one of them.
To create a project you can follow the repo readme, it's only 1 command :)Repo link: https://github.com/vanflux/vf-ext
Recently I made a jstris bot extension using the framework, you can checkout it here: https://github.com/vanflux/jstetris-bot
Could this be useful to you? What can I improve on that framework? What features could be good to have?