We tried to blacklist *.woff files when investigating, but the blacklist had no effect. Looking closer, it seems that for resources in CSS files:
- Black-/white-listing has no effect.
- The resources in those files inherit the stylesheet's UFI and ignore the ones defined in CDN
To demonstrate, use the following Unique file identifier generation:
All .png files from stylesheets will be served with a "drupal_cache:xxx" UFI instead of an "mtime:xxx" UFI.
(might be a documentation issue instead of a bug)