That would be... difficult. You see, the "raw" soulform on Mechanus that Primus draws from isn't a soul shell like on Baator, or an ambulatory creature; it's his own energy pool, where the power to create a new modron resides fully. A new modron is automatically created whenever one is destroyed, and the pseudofinite numbers of the modron ranks mean Primus has a hefty stockpile of soulstuff to draw upon.
Formians aren't an exemplar race; unlike the baatezu, they don't spawn that way and never have. It's possible they could devise a way to convert souls to workers, but it would be difficult to call that "lawful neutral."
Fiendish Codex II has a brief bit of insight into it, incorporating lots of torture followed by being flung into a death pit to be devoured and extruded as a lemure.Is there a source which details the process of creating a lemure more thoroughly?
See, the awesome thing about Planescape is that you might bump into some of those adventures as early as 5th level.
Any basis? None that I can recall.In that vein, I have one: is there any basis for being able to "steer" a demiplane around out of the Ethereal (or into the Deep Ethereal I guess), and if so how far could you go?
That would be J'zzalshrak, the Errant General. There are a few demon lords such as Baltazo who have dabbled in the Blood War, though Baltazo himself is retired and pretty happy about it.
Well, you're wrong about that. As I've tried to point out to you.Because I still think the evidence suggests that the ONLY thing keeping Baator intact is the Abyss's collective refusal to buckle down and get the job done.