To enable the use of aggregate dependencies you will need to make a Surf configuration change. By default the capability is disabled in Surf and is unlikely to ever enabled by default in future releases of Content Services.
To enable it you set the following line within the Surf configuration file, webapps/share/WEB-INF/surf.xml:
<web-framework> … <aggregate-dependencies>true</aggregate-dependencies> … </web-framework>
Note: Any third-party modules or add-ons that have been applied might
not support this feature.