Hi Jim,
My current understanding is that /lib adp includes cannot be shared across packages within the ACS templating system, as a security measure etc. If true, then acs-subsite seems the most appropriate location, since the include is relevant to the master templates. If there's a better way, please let me know.
The meta_defaults provide default meta tag values if unique ones are not specified. The defaults should be called just prior to page rendering (to provide the greatest opportunity for setting by page related calls). The blank-master seems the most logical place. They could be controlled by a parameter, and not utilized by default.
