Lots of good ideas.

I’m a fan of stow-like tools, but there are advantages to using something like Salt (or similar) if you’re dealing with VPSes that share don’t common configs like firewalls. There’s a lot to learn with things like salt/chef/puppet/attune/ansible, whereas something like yas-bdsm, which is what I’m currently using, is literally just:

1. Keep your configs in a git repos, in a structure that mirrors your target
2. Run a command and it creates symlinks for the destination files
3. Commit your changes and push them somewhere. Or just restic-backup the repos.

The config file formats are irrelevant; there’s no transformation logic to learn. Its greatest feature is its simplicity.