Is the mechanical pop assembly from the Assembly Lines supposed to be Empire wide? I mean the wording on the tooltip makes me think it could be a mistake but they are expensive enough that it could be intentional.

But if they are meant to be this way, then even for 10 alloys and 1 crystal, empire wide assembly speed is too powerful, literally one of those districts will tripple the mechanical pop assembly of an organic empire that has a robot factory on every planet. You need like 6 planets and that district is more alloy efficient than robot factories. And pop assembly is super powerful, there's a reason it's limited to one per planet buildings, it's unaffected by planet capacity, you're just printing dudes, it's busted.

However you do these, they're going to be powerful, personally I'd probably give them like 4 pop assembly tops, and have them only give that to the planet they're on, yes it's way less alloy efficient than a roboticist and there's a crystal cost but you're getting ship build speed and the ability to fill a whole ♥♥♥♥♥♥♥ planet with these guys, which is insane but i love it.