The building cranes seem only to fetch items when the item under them is not full for the next yield. If the number of items per cycle is not divisible by the number of cranes fetching from the belt, the remainder of cranes skips a fetch, reducing its effective throughput.

This is an extremely annoying issue to have in an automation game.

It is unacceptable because:

1. The ingame UI does not reflect that in any way. You can setup a 3 input/cycle recipe factory with 1 crane and it will work fine. You double the number of cranes, the UI shows the estimated product rate double, yet the building works at at 75% the promised rate. If you do upgrade a 4 input/cycle recipe from 2 to 3, the same thing happens.

2. It punishes the players trying to maximize cranes per building while maintaining the crane proportions according to the recipe.

3. It makes sushi belts extra-prone to desync and excludes the scrapper-at-the-end solution as cyclic crane hitches will leave unattended items at the belt ends. It is extra painful to deal with when the sushi belt moves "multimodules" that are cut into pieces on-site to reduce the belt connection footprint and the cut size is different for different modules.