Warning: I'm non-professional; not crew, not engineer - just guest here, thanks.
The thread has now turned to an area that intrigued me some time ago (419, page 21) and caused me to write the following.
An article on smartcockpit, written by an Airbus employee, on Low Fuel Temperatures has a table listing the Minimum Inlet Temperatures for engines from various manufacturers. RR has temp of 3C (This figure seems generalised for RR).
The question, for those that really do know the answer, is what happens next if the fuel heat exchange systems cannot raise the fuel temperature to, or above, 3C?
The question was not answered then but I'm hoping one of you will be kind enough this time.
Thanks in advance.
Regards, Tanimbar