> have all been shaped heavily by human blood

This assumes the lessons were specific to the body type and aren’t generalizable?

Even small changes to time tested designs provide significant risk. A completely new body style will inevitably provide completely new failure modes.

Pressurizing a tube vs pressurizing a pancake (or flattened sphere, or some other easy approximation) will have very different mechanical loading characteristics. Turbulence (differences in air speed/pressure) across a large flat-ish surface that also has a signifiant pressure differential will also prove challenging to design for and scale up.

Aerospace is a very high dimensional design process. Doing anything different puts you into unknown territory real fast.