The only important thing is what it wrote in Pilot Operanting Handbook.
Depenting of aircraft oil/heat exchanger is not enough to ensure safe operation.
(See crash of Boeing 777 at heathrow few years ago.)
Last september, we don't put Prist in tank (lack of time
) Fuel Temp on Ground 15°C, Total Fuel Quantity nearly 2600 Lbs. After two hours at FL260 , OAT-30°C, both fuel pump came "on" and fuel filter by-pass pop out.
30 minutes later we were safe on ground and only during taxi, Fuel pump came "off".