Feature branching using git subrepos

Question

I have a project which is using git subrepo: https://github.com/ingydotnet/git-subrepo and I'm trying to figure out how to implement feature branching as a dev workflow.

Here is what I have so far:

1. Create a branch in the monorepo
2. Make your changes in the monorepo
3. Make a pull request for your branch into master
4. After the pull request is merged into master, run git subrepo push --all to also push the commits to their respective repos

Does this sound right? At no point have I had to use git subrepo branch or git subrepo commit so I feel like this workflow isn't actually the intended workflow for feature branching with git subrepos. If the workflow I've suggested is correct, what is the actual purpose of the subrepo branching and committing commands?