While observing my factories, I noticed that:
- I had put them on a "build one of everything" circular queue
- out of the 12 ships, 10 classes were fully built
- whenever the queue came to a class that was fully built, it would consider this for about 0.5 seconds then skip to the next
So a full round took 5 seconds longer than if I would have only the two buildable ships in the queue. Given building speed in this game, this is a noticeable lag.
Seems a bug to me: micromanage factories run faster than non-micromanaged