Here is the related JIRA: https://jira.jboss.org/jira/browse/RF-1941.
As for now, you can:
1. switch off standard skinning, so you'll get a single CSS file.
2. set load strategies to NONE for both scripts and styles resources and place them anywhere on the page.
3. use this: https://www.jboss.org/community/wiki/MavenResourceDependencyPluginReference to minify volume of CSS/JS content downloaded.