[keycloak-user] Keycloak theme - properties from env / external file / client?

Hi there, we have a custom keycloak theme, which contains a link. The link needs to be different per environment (prod, staging, dev etc). Having a separate "theme.properties" file per environment is not really an option for us, as we want re-use the same Docker image. So.... Can we access environment variables from "theme.properties"? i.e. OUR_PROP=${env.SOME_ENVIRONMENT_VAR} Or is there a way to read values from an external file? Or can we access a particular Keycloak client's redirect url? i.e. in our case client="Cipher2". Or any other ideas? I'm not too sure how the Java SPI stuff work, so any pointers would be really appreciated. Thanks! Ben