X-ray hit replays suggest that the projectile passes through multilayer composite armor as a single volume, entering at one point and exiting at another, without accounting for layer-by-layer interaction. In reality, an APFSDS round should progressively deform and erode while penetrating each armor layer.
Because of this, multilayer structural armor does not take into account the projectile’s impact angle, its residual velocity, or the generation of fragments after the armor is penetrated.
In the second case, we can see that the side armor of the Abrams turret is effectively not protected at all, even when the projectile enters at extremely steep angles.
I also noticed another issue with multilayer armor: even when a projectile penetrates the armor at the very limit of its capabilities, it does not appear to lose velocity and can continue to penetrate almost the entire tank, while still retaining the ability to generate multiple fragmentation waves.