Having basically the equivalent of an agent in your corner would be a very valuable service, but crucially this agent would need to have an impeccable reputation, hence any of the usual recruiters only "doing secretarial work" wouldn't work. They would need to be genuinely well connected professionals.
I can see an ongoing relationship with salary increase negotiation support, a bi-yearly in person strategy session ("It might be time to move on") as well as genuinely going to bat for you in terms of your contract ("hey, let'a push for a 7 year exercise window instead of 90 days")
Anyways. I don't know if such a service, but it seems like it should exist.