I can’t tell you exactly which ones now but half of the missions I do, gave nothing now at my play.
LotA weapons are different thing. You need story missions, mining missions, defending missions, mining and holding the sites to manufacture those cheap weapons. All those missions are getting all my resources as I am using most of fire power at those missions… and even I hold 4 of them, I still can’t manufacture a weapon… when It asked me to have a special site to manufacture one, I just gave up… As we talk about this DLC somewhere else, we don’t need to talk about that here.
A hard missions makes me lose 250 material to about 100 tech… If I lose a weapon, it’s much more. Just 2 of those missions without any resource back cripples you enough.