The local_lib was supposed to be a very temporary solution, since we absolutely needed DataCite harvesting feature in a release.
For various reasons there were some delays with making a new xoai release, so the jars in local_lib are still in use.
However, xoai 5.3.0 is about to be released. And, most importantly, my PR 285, that provided the extra features that Dataverse now relies on, for DataCite and similar cases, has finally been merged into the xoai develop branch. Which means that we can build with xoai 5.2.3-SNAPSHOT releases, and can therefore lose the local_lib already.
I will make a PR shortly.