I have been wondering what "good seed" even means in current patch, what with changes to crises and all. Since the Luddic Majority bonus only cares about Mining(Luddics are apparently perfectly fine with AI core administrators, nanites in the soil they farm and embryos in the factories they work) it means it can be stacked with all other bonuses as long as Mining can be moved off of the habitable world. This means a system with either two habitables(at least one with organics) or even better, a system with the elusive organics toxic planet since then you can also slap Autonomous Mantle Bore on it.
This is in addition to all the other stuff(no atmosphere, gas giant, superhot, etc.) Orbital-wise, you want a) a Gate, b) a Wormhole to Limbo and c) Comm Relay at the very least; so the specific requirements will vary depending on what you get and how many stable locations you have.
Note that since all the crises can now be be permanently dealt with, there is no more incentive to keep everything limited to a single system, although you'd still want it all in one constellation at least just to save on travel time/fuel.