Not sure if this advice really applies, given i haven’t used Git for any reports myself and I don’t know how you are doing the text based project. I did pretty much all my uni reports in a online latex document site which allowed shared editing, so there was some history but all edits were live to the main doc.

But with the power of latex at least, you can have the main file do import and usages, and maybe some setup. And then combine other files representing anything you want. Such as one for front page, one per chapter or one for appendixes.

Then just can do changes/new sections in feature style branches, and it’s up to you if you want things to go to the main branch, or have a dev like branch where further refinement can happen if your work is structured and not all over the place like my report writing was.