When enabling Blueprint Sandboxes with both PM and BZ's Zirconium, there is an error on load:
"Failed to load mods: Error in assignID: entity with name 'zircon' does not exist. It was removed by periodic-madness.
Source: bpsb-sbr-zircon (selection-tool)."
Also of note is Extended Descriptions being affected by this, but only with Blueprint Sandboxes enabled.