Hi Steve, I have a suggestion, but im not sure if it was proposed already some time ago.
It always looked a bit strange for me that meeting aliens all we can do is diplomacy, so I think that it would be great that, lets say, after meeting aliens "Tau" we will get some custom research project.
Possible projects:
Tau ship design - shows up after first ship seen and helps identify their ships better, or even prohibits full identification until researched
Tau physiology - appears after first tau are either captured/killed in ground combat or when trading agreement is reached. Can give some modifier for fighting them or just provide some insights for diplomacy.
Tau Culture - appears after good relations are established, increases diplomacy rating.
Tau technology - appears after first tau ship salvaged - gives more info on ships and maybe some bonuses to other staff.
etc. many things can be done here.
I believe this will enrich interaction methods with NPR.