This is probably a dumb question, but /var/lib/docker/volumes/fleetdm_data/_data appears to be full of cpe.sqlite\d{10} files that are 245M in size. a) what causes this to happen, and b) how should I keep these to a minimum?

This is the vuln db from NST, it should only be downloaded once. It's possible it can be downloaded across each instance of fleet, worst case scenario.

Ok; thanks - this just means I can delete it before upgrading fleetdm without worry.