Might one, perhaps, check the pedigree of the question?
Have, similarly, checked all my written info and there is nothing which provides any sort of tie-in. I take your point of the #1 tank temp and heat exchanger relationship, but Boeing obviously don't see any problem there since lack of a Fuel Temp display is acceptable for dispatch as long as there is an accurate SAT/TAT available.
There's nothing in our MMs which indicate any sort of cross coupling between hyds and fuel - other than the tank 'spaghetti'.
If the question source is reliable, and you get an answer (and the reasoning !) would appreciate a posting of same.
