In any case, my observations are only anectodal, and are based on
homebuilt aircraft. Boeing may be using advanced epoxies with superior
thermal and mechanical properties. If that is the case, it would be
trivial for them to put these concerns to rest. I hope that is indeed
the case, and that the 787 is not built with the same epoxy I am using
on my homebuilt.

Did you lay your composites up on a frame and bake them at high
temperature and pressure in a giant autoclave to cure them? If not,
then I bet you aren't using the same materials or processes...