[Feature Request] Environment variables or bolt parameters in extension configuration file

[isaac-mason]

Is it currently possible to use environment variables or bolt parameters in the /config/extensions/boltforms.bolt.yml configuration file?

As far as I can see, this isn't currently possible. I am currently using an initialisation script to replace placeholder strings with sensitive ReCAPTCHA credentials.

If this isn't possible, is there any reason this hasn't been done, or could this be an addition to this extension?