As we move toward this goal of infrastructure as code I would love to see the official slack plugin support configuring portions of the setup in code as a file that sits at the root of the repository.
A good example of this would be how codeowners handles setting up default reviewers.
In our use case, I would want owners of a repository to have the ability to set the slack channel as well as creating and managing a slack group. This would allow teams that want to ask questions about that repository and get help with something without having to manage this outside of the repository.