I have noticed a bug when interacting with a minor faction.  I am able to assist them constantly even if I have already completed a quest and assimilated them.  Is this intentional?

Additionally I have assimilated the Baghaba and have the ability to transfer one of their population to my nearest planet but since I am Vodyani should this occur?  it works and I do get a Baghaba which also function in same way as other workers (is on multiple planets at once) but I thought Vodyani dont allow any other race on thier ships so is thi  abug and if so what should happen? or should the Vodyani have a differnt interaction where they get essence when the worker gets there (as they consume it)??