Nanite transmutor building that creates 2x of motes/gases/crystals for 1 nanite resource seems to work just fine without them. I have one in my empire, but I run out of nanites (because they vanished after I terraformed a nanite world). It still works and produces stuff even with me having 0 nanites. No error messages.
Now I look at the strongest economy AI empire and they actually experience food and consumer good shortages and all their pops are at 0-10% happiness. They are somehow far ahead of me in economy score because they have 4-5 nanite transmutors on every single planet they have and probably tens of thousands of every rare resource. They have no access to nanites whatsoever. Fake economic strength :/
Now I look at the strongest economy AI empire and they actually experience food and consumer good shortages and all their pops are at 0-10% happiness. They are somehow far ahead of me in economy score because they have 4-5 nanite transmutors on every single planet they have and probably tens of thousands of every rare resource. They have no access to nanites whatsoever. Fake economic strength :/