externalize the database connection details for Database providers

What kind of database provider are you talking about? A Custom Provider (provide single values in value holders), or are you referring to something else, like the Database BOM?

If you need to externalize the config for a custom provider, you can handle that yourself by looking up a known config file, an environment variable, etc. You control everything about it, as you wrote it yourself.

For the Database BOM, I don't know.

Regards,

Jostein