Storing all secrets in separate file

Is it possible to store all secrets from files in /etc/config folder in a separate file.
For example specify in /etc/config/wireless

	option key '$guest-wifi-password'

and somewhere else

guest-wifi-password: password

It can be useful if you want to store configuration in git.
I know that there is an option to use git hooks to inject/extract passwords but probably there is more elegant option?

No, this requires too many changes, up to reworking the current setting management paradigm.

You can use a local/private Git repo, or take a different approach.