Maybe aluminum is a better option for the cruisers
That's one way around the problem of HEAT ; another way would
be a can of White spray-paint !
I use white paint on the surface of Any part that has a foam-core ; even
though my MGS epoxy IS an aircraft grade, because foam can melt at
a rather low temp, (black carbon + sunshine = Heat )!
Nomex-honeycomb core or
solid carbon parts, i don't worry about heat with the epoxy i use.