The Idanians are a secretive species that has limited contact with outside civilizations, but are part of the Quadrant intrigue as even the Orion Syndicate has tried to infiltrate their society. However, the Idanians are well-informed due to their spy agency, Idanian Intelligence. Their agents have been known to alter their physical appearance surgically to pretend to be other species when they infiltrate other cultures. The use of dataports also allows them to tailor the memory of their agents, so that even the agent believes themselves to be their cover identity.
Their only appearance was in the DS9 episode, “A Simple Investigation“, and as they are a secretive species, a great opportunity for you to invent cultural background. All of the Idanians seen on-screen were Idanian Intelligence officers, but there might be individual Idanians who have sought out Federation citizenship. They may also be masquerading as another humanoid species, and might not even realize it in some circumstances (where they already have a dataport installed).
The Dataport Talent does not have to be limited to Idanians. It’s similar to the Neural Interface Talent on page 41 of the Sciences Division book, but with some differences (such as memory editing, different bonus, and deadlier).