Send units ahead takes the quantity you type

Type a quantity into Send units ahead and it stays. Send ten units on from a stage of two hundred by typing ten, and the button confirms the number you chose. Type more than the stage has left to give and it settles on what is actually available.

Before this, the field snapped back to the number it opened with as soon as you clicked away, so the only route to a smaller batch was one press of the minus button per unit.