I got the event where it says that you discover a precursor artifact that can terraform a tile on all of your planets. I'd hit it before, but was playing Benevolent at the time so didn't try to get the additional tiles. This time, though, I was playing Malevolent, so I chose that option. I thought that what it was telling me was that I would get one usable tile automatically added to each of my planets, at the cost of dropping my production by 90% for 10 turns.
After choosing that option, though, I didn't see any new tiles on any of my planets, and my production didn't seem to drop at all. Is this a bug, or am I misunderstanding what that event is supposed to do?