I don't know if these would have whipple shields or panel lines. The lore apparently states that stuff is often cast in solid bi-phase carbide blocks along with cabling and devices. So maybe no repair hatches and modules. But if BPC has a density of 1.55, then it might make sense to leave some air pockets if stuff needs to float. Separate layers/scales of BPC might also make sense if it tears and unravels as suggested.