I am currently building a Drupal 8 application which is running outside Acquia Cloud, and I noticed there are a few 'magic' settings I'm used to working on Acquia Cloud which don't work if you aren't inside an Acquia or Pantheon environment; most notably, the automatic Configuration Split settings choice (for environments like local, dev, and prod) don't work if you're in a custom hosting environment.

You have to basically reset the settings BLT provides, and tell Drupal which config split should be active based on your own logic. In my case, I have a site which only has a local, ci, and prod environment. To override the settings defined in BLT's included config.settings.php file, I created a config.settings.php file in my site in the path docroot/sites/settings/config.settings.php, and I put in the following contents: