Custom reports installed as /opt/opennms/etc/report-templates/*.jrxml will automatically get compiled into *.jasper files on the file if needed, but the same is not true of subreports installed into /opt/opennms/etc/report-templates/subreports/. Obviously I can compile the subreports myself and drop the .jasper files in place, but if it's a small effort to do, it would be handy if OpenNMS could auto-compile the subreports too.