Searching email with fulltextsearch

Hi,
I have modified the email app to use fulltextsearch as the underlying search engine if it’s installed. It supports searching attachments too. I have it working on my local server, and it really improves the email search experience.
But I don’t know how to make this available as a pull request. It required some changes on the mail, fulltextsearch and fulltextsearch_elasticsearch repos and there are a bunch of different branches on each, so I don’t know if I’ve targeted the correct versions.

Is there any guidance on how the branch structure work?
Should requesting PR’s for these kinds of enhancements on main branch or the latest release?Any pointers would be appreciated.

Regards,
Frank.