Davidoo I have a 24 ST and mine does have the cooler with the hoses and electric motor that circulates the engine coolant through the PTU. My 21 ST had the same configuration. When you shut the vehicle off this electric motor continues to run and circulate coolant through the PTU to possibly help with heat soak. I climbed under the car after I shut It off and heard the electric motor running. I don't know how long it runs.
Personally, I wouldn't worry about the studs. Ford wants to make as money as possible so of course they want them changed. They could probably be re used multiple times without any issue. Be sure to use blue Loctite and torque them to spec.
What I can't figure out is why your vehicle does not have the cooler. Also, I don't know how much the cooler helps as it takes circulates hot 200-degree coolant through the PTU. How hot does the PTU fluid get?
I think Ford attempted to do some last model year fixes to help the heat issues they had with the PTU? Just unsure why your model year did not have this mod.
One good thing, your setup allows to drain the PTU fluid easily,