I got to open communications with the Precursors. Conveniently, that changes the name in the database to the Precursors. Haven't been able to move diplomatic relations further to the positive. I have a couple espionage teams on one of their outposts without any complaints or results.
I am not sure if they ever detected by 250 ton scout on actives, but their outpost should have detected it on passives since it orbited their outpost. I am torn, they haven't done anything hostile, but I don't know what will provoke them at this point. So for now, I am exploring on other chains. I will prob use missile drones to survey their outposts.
I expect I will attack them at some point, but there is a minor difficulty:
Unlike games where they attack my scouting and survey forces, I won't have a way of determining either the number of armed ships in the system or what they are armed with. All I know about is one active sensor, and the speed of one ship that was able to track that active sensor.