Going over the Block Core List, I found some stuff.
Counterparts: Some of the pre-made counterparts have the 'Counterpart' tag twice for some reason.
Equipment: PADDS and Tricorders should be their own 'equipment group' on the database - there are a lot of cards that look for 'any tricorder' or 'any PADD' and it'd be easier to find them if so.
Time Locations: Time locations are only intermittently listed under 'personas' on the mission pages - like none of Earth's time locations are listed on any of the Earths.
Orb of Prophecy and Change
(Dom) (HF6) - Dominion and Homefront 6 versions lack the 'artifact-equipment' tag.
History Repeats Itself - Database text says 'Melkatians' instead of 'Melkotians'
Mr. Tricorder - the 'any Data' link just has all cards of the Data persona and all cards that has the word 'Data' in it even if they're not referring to the android - also Eli and Frank Hollander need to be mentioned for they count as 'any Data'.
Borg Queen - None of the Borg Queens have the 'Borg species' trait.
Four of Nine - Missing 'Species 571' tag.
Locutus of Borg (Fajo) - missing 'Borg' and 'Human' tags.
Evek (HF2) - Is Capturing-related, but doesn't have that tag.
Founder Agitator - lacks the Shape-shifter tag (all changelings should have it by default)
Tomalak (HF3) - Not tagged as U.S.S. Enterprise-related.