Thanks for the clarification.
For Unique Treasures does the No Duplicates rule apply per player or for the treasure pool for the particular game? I.e. can you have multiple copies of a UT in the same game if different players bring them?
In general, the No-Duplicates rule is only applied on a per-player basis, so two different players could add the same UTs or use the same ships/crew/etc..
Normally you’d have no idea going into a game what the other players will be using in their fleets or what they’ll contribute to the treasure pool, so there’s no good or fair way to enforce that rule globally if two or more players wanted to use identical things, without switching to a full drafting format (or similar).
There are a few edge cases and nuances to the rule, but they’re relatively minor and mostly obvious (page 7 of the PC and the second post back on the very first page of this thread go into more detail).