We are using the metadata deploy for concepts (4500 items) with a MIRROR import configuration just like RA.
However we have noticed that all the concepts are installed at Tomcat restart, yet my understanding is that the concepts are only re-installed when the version changes.
Using Platform 1.11.6-SNAPSHOT, MDS 1.2-SNAPSHOT, metadata deploy 1.7
@darius correction I am using similar metadata deploy code as the RefApp for other packages, Locations, Roles, Encounter Types etc that are defined in packages.xml
Looks like my concepts are not installed, with no error message so I will open an issue on JIIRA