Any chance of getting a playable changeling? There's at least 100 changelings that grew up away from the Great Link, only 2 of which we actually seen (maybe 3).
Just give them the attacks used by existing changeling NPCs, an innate Holoprojector-like ability and customization like an alien character to cover their shapeshifting and the things they're best known for are sorted.
STO is about my Liberated Borg Federation Captain with his Breen 1st Officer, Jem'Hadar Tactical Officer, Liberated Borg Engineering Officer, Android Ops Officer, Photonic Science Officer, Gorn Science Officer, and Reman Medical Officer jumping into their Jem'Hadar Carrier and flying off to do missions for the new Romulan Empire. But for some players allowing a T5 Connie to be used breaks the canon in the game.