I have seen heat and pressure warpage on parts including full fairings. Most of my parts have been pretty light duty.
Carbon (presumably fiberglass too) in an epoxy slurry is not the most stable of materials. We might consider the part to be cured in 48 hours when it comes out of the vacuum bagging or when we say that it is done with a wet layup. The epoxy works by the combining of the two parts of the chemistry. Eventually the chemicals become immobilized But I doubt if they are completely reacted. I think that rigidity keeps improving over months if not years. These chemicals are encumbered by their own rigidity.
When I first started doing composite work I got a tape and kit that was produced by Burt Rutan. He went over the processes that he used successfully in building light aircraft.
Aerospace users now use the prepeg type of layup with many tons of pressure. I doubt if those military or high end commercial planes have much trouble with heat/pressure induced flex.
I am not so sure about using too many dissimilar fillers, coefficient of expansion type of problems. I caught my wife using spackle on our Varna Streamliner. She was getting close to a deadline and needed something that would dry faster than the epoxy.
When we have sanded the body down it has a lot of colors in it.
Not sure if I answered your question very well.
