I have been working on this post-install script, which was inspired from the documentation on Getting Started ( https://docs.wordops.net/getting-started/post-install-steps/ )
Feel free to take and modify if you like.
I have a clustered configuration for the frontend servers, which is why I share the /uploads folder via EFS. I found sharing PHP files across EFS slowed down WordPress significantly and have resorted to a more docker-style configuration. New sites, new plugins, new themes, etc, require an AMI update to be served.
I'll be doing a blog post on it in the future. It's a pretty sweet setup