I don't quite understand if these are worth it at all. I recently captured an independent lvl 8 ocean world with trace trillium and designated it as a autofac. It had an efficiency of only ~12% though. However, it could make it's own ends meet and leave a small export. It must have been a natural level 9 and it went up in tech level immediately. Then I noticed that it could no longer produce enough for itself. The only industries on the planet were the autofac and trillium extractor. I ended up having to destroy the arcology on it in hopes that the lower population would help with the lack of essentials, manually dump excess resources from my other planets and set it up to import the essentials from another planet (also had to redesignate this other planet and take the efficiency hit).
My question is, when are population structures worth the hassle? Is there another way of handling my situation that I missed? I have a tiny empire with three planets and the independents around me are far too strong for me to deal with right away.
Now, the game won't produce enough luxuries because of lack of trillion. I dumped a zillion tons of food and durables but the game isn't smart enough to either make more trillium or to give higher priority to trillium over food/durables. Ugh