I did exactly that. I have three pit probes and two food probes to start with. In the Assassin 28, it appears that there is a 30-45 degree temperature differential between the bottom and top shelves in my six shelf unit.
PIT-1 is in the middle and is my blower control probe, PIT-2 is on the bottom rack at the back and FOOD-1 is on the top shelf (acting as a pit probe while I season the new 2
I have a third pit probe which I plan to use to control another cooker. I'll probably install all five probes int the 28 during the next few days to get an idea of the temperature hot/cold spots.