It doesn’t take much effort to select materials for a part that has to support its own weight in a 1.25-1.5 g loading environment + a secondary enforced deformation loading.
One vs two piece CF plenum designs
If you can’t design a bonded joint capable of developing the full strength of 1 or 2 plies of a CF fabric then you should not be designing a 1 piece CF plenum. I’ve designed and tested CF-to-Inconel adhesively bonded structural assemblies that had to survive 11 Kelvin (-439.8 degF) and operate at 19 Kelvin, and required bonding multiple complex CF structures together. A 1 piece monocoque design by itself doesn’t make it inherently better than a 2 piece design.