Minimum limits
We have also seen teams using a minimum limit, that is, a signal to tell that there is not enough work for the station. This is used to level out the flow. The minimum limit becomes a signal that we should help the workstation upstream not because they are reaching the maximum limit, but because there is a risk of the ketchup effect, first comes nothing and then everything comes.
For teams that have been working some time with limits, the limit itself is not of the most important thing; it is instead much more important to see the whole picture and start discussions about how to level out the workflow and improve the flow.