Added 4 minutes later
I noticed another interesting feature. If you capture a Hivemind, they are automatically genocided, one by one, even if this policy is not allowed, and this cannot be reversed. There's also this note: "These brainless drones are incapable of integrating into society." And the Observers don't care at all; it doesn't even affect their relationship with them or anyone else.
By the way, has anyone created megastructures? Are they worth it, or are they too time-consuming to build?