I would like to suggest a new service module.
That service module should be an “Agent communication nexus”.
A medium citadel should be able to maintain communications with a single agent, large one with two and the xl one with 3 agents.
The way it should work is that only npc corps that you have enough standing with, would be able to sell an agent communication uplink that can be attached to the nexus. The agents would just be non descript agents of a certain level and type (except storyline).
And the caveat here is that while you can do missions from the citadel, you won’t be able to spend lp at the citadel. You would need to go to an existing npc station for that.
Agent rewards can be taxed by the station owner.