When I initially coded up WARCreate, the webRequest API was still experimental. I believe there are more mature APIs that can be used from the extension context but some require DevTools to be visually open, which is not a common usage pattern of a typical web user.

Per the ticket, we have worked on a few other JavaScript-driven web preservation project like https://github.com/N0taN3rd/node-warc and https://github.com/N0taN3rd/Squidwarc, among others.

Web archiving from a browser extension is difficult but can be improved. I don't know of any other approaches at trying to do this via a browser extension beyond submitting a URI to an archive.