Hey James,
The MQ depth is labeled "Command Queue depth" in the dashboard. I just updated the docs to make that connection explicit, so your link should be updated shortly.
That page isn't intended to document the dashboard specifically, so not all the fields are described. We don't really document the dashboard in a centralized place, but I like the idea and I made this ticket to create one
https://tickets.puppetlabs.com/browse/PDB-1285Catalog Duplication specifically is dupes / (dupes + new), where dupes and new are both counters that are respectively incremented when a catalog is stored with the same content as one that has already been stored, and when a catalog is stored with original content.
Both counters start at zero at startup and only apply relative to catalogs processed since startup.