The linked tool git-branchless handles this pretty well (https://github.com/arxanas/git-branchless, I'm the author). You basically run `git checkout <branch>`, `git commit --amend`, and then `git restack`. This will rebase all dependent branches. As long as you're not using merge commits, you won't have to resolve the same conflict more than once. (It will also warn you up front whether or not merge conflicts will need to be resolved; you can pass `--merge` to start merge conflict resolution.)

To rebase your commit stack on top of the main branch, use `git sync` instead of `git merge`. Merge commits often make it so that you have to resolve conflicts multiple times.