TL;DR
Add into the tooltip that appears when you hover your mouse over "Trash Unrequested" the information that if a maximum value of a request is set to "inf.", then all items above minimum would be put into trash.


What?
The appropriate fix would be to add this to the description something in ...

When having personal logistics request with maximum value set to "inf." and "Trash unrequested" is off, then the maximum amount of items you can have will be infinite and they will not be automatically added to trash slots. Though, if you turn on the "Trash unrequested", all items above the assigned ...