Pull Requests
These are also known as Merge Requests (MR) from GitLab because they want to call it differently. Basically, a pull request is someone else proposing changes to your writing that you can review, inspect, go back and forth until you are happy, and then merge into your main
branch.
I haven't used pull requests much with writing, mostly because I don't have editors that also work with Git. But, the theory is if I did find such an editor, they could make their changes to my stories, altering and fixing, and then push up the request. After that, I could comment on sections, figure out answers, and then eventually accept them.