We have tested this logic level converter more for 5V logic on the high side. Looking at the datasheet, the absolute maximum rating for the drain-source voltage is 50V with 0.22A continuous drain current. It should work for higher voltages based on this fact. We just have not stress tested this setup so we are not sure about how efficient it is when using 12V and 24V on the high side and 5V on the lower side.