I thought I was nearly finished reading this thread when I got to post 65… 
I like having a backup and a (git) version control history of my configuration - one of the main “myths”.
Request: What I would like to see is documentation that describes this use case, including how to migrate from one system to another, restoring the backup/state (repository) from the first system.
I had an SD card fail recently and had to recreate my system from my repo. The configuration YAML files were the easy part. The settings, other program installs, etc. that I had to re-do were the hard part.(So I added more detailed notes for myself for next time.)
I’d like to see docs that show how to migrate HA systems easily. Thank you!