How to declare quarkus properties which are fixed at build time?

[ls-bit]

In our project we are including some features like licensing, and it would be great to use quarkus properties to allow to easily toggle these features on or off in dev mode and in tests via application.properties.

By default, it seems properties defined in application.properties can be overridden e.g. with environment variables etc. We want to prevent this in our case, since we will ship binaries to the customer and want some properties to be fixed at build time.
Is this possible without writing an extension?

From reading docs @StaticInitSafe or a custom config interceptor could be the solution?

What would be the recommended option to declare properties which are fixed at build time?

Edit: @StaticInitSafe does not seem to help in our case

[dmlloyd]

The best solution IMO is a config interceptor with a high priority which records these values and is included in the JAR. If the priority the priority is Integer.MAX_VALUE then it will not be overridable. Just be cautious not to override keys outside of your key space.