...I wonder how bots would fill a furnace requiring 10 prod modules, 10 eff modules, and 10 speed modules? a "race condition"?

Maybe this is one of those "just don't do this" bugs. But the not-a-bug I linked is getting really annoying right now for me, since I don't have bots, but I do use blueprints.
I assume a fix for this would require fixing the not-a-bug I linked above (which sure seems like a bug).