The operations on the Xpp3Dom class have been improved with https://github.com/codehaus-plexus/plexus-utils/commit/6dfc0a66a763d25ab534c8f8b223e465bbf9779e so it's worth integrating those.
Speed improvements while parsing big reactor projects
NullPointerException when pom.xml has incomplete XML tag
Maven XML parser does not accept '>' in XML processing instructions
Upgrade plexus-utils to 3.2.1
GitHub Pull Request #271