VM License Auditing Best Practices?

I've recently inherited responsibility for a large number of FortiGate VM licenses in a recent organizational merger. I'm attempting to go through the list of licenses in the support portal and validate which of them are actively in use, and which of them are available to be used, but I don't see a simple way to do this. A few quick Googles seem to point me into having to check licensing status from the firewalls themselves (but this would defeat the purpose because then I would already know they exist). I'm hoping one of you knows of a report somewhere I can run to see which licenses have actually been consumed.