Just another ancient engineer here.
Remember Concorde? Mach 2? Total temperature up to +127°C and structure temperature up to 100°C + ? And yet...
I dived into the fuel system of the Concorde not too long ago.
(Somebody asked me. I'm not a fuel system engineer but I can read system diagrams - thank you.)
Even Concorde had arrangements to keep residual water mixed in with the fuel, rather than letting it settle in "inaccessible" places.
So I AM following this with interest... hoping there will be an answer.