With CLOUD-1479 we deprecated CONTAINER_HEAP_PERCENT and INITIAL_HEAP_PERCENT. However the image metadata was only updated to reflect this for webserver 3.0.; the 3.1 image YAML files carry the original environment variable descriptions.

The necessary script changes were performed since the JWS 3.0 and 3.1 images share the same scripts.

I don't know (yet) whether this is reflected upstream in any documentation.