I have yet to find even one NPR (not spoiler races) who is willing to "exchange information" with me in C#. Nobody I've asked yet has found such an NPR, either.
Here is a test game I set up with
seven game start NPRs on v1.63 who found Sol quickly due to the random stars bug on that version. These are natural NPRs that were created automatically by Aurora at game start, not SM-added. Diplomacy cannot ever progress because none of them want to exchange information:

I'm starting to suspect there's a bug preventing NPRs from being willing to "exchange information".