PSA: If anyone is seeking for a good place for meta-alloys, HIP 17862 11e in the Pleiades has a Thargoid structure with 9 "organic structures" that yield them. 5 near and around the central structure, 2 on the slopes immediately around it and another 2 farther out counter-clockwise from the "leviathan" near the "bones" surrounding the central pit (a bit tricky to find; scouting from air with night vision helps).

There might be better places, haven't scouted many, but of the handful I have, this has the most. The nearest inhabited system is 10 ly away.