Hey Akos,
Depending on the size of the extension yeah would probably go with React.
You can set the permissions to be only on Twitter and inject on then.
The pro about React is that it's a bit more flexible to make changes.
Do let me know if you want to discuss it in person, happy to help where possible.
Ákos Kőműves
Full-Stack Developer and Writer
Thanks for sharing this, Chris!
I'm building a browser extension that manipulates the DOM on Twitter.com.
How would you approach something like this with a React-based browser extension?