Hail Yeah back under the knife

[FLexpat]

Think of the trapezoid as a softer edge that goes all along the bottom of the bulkhead and already has a fillet attached (no putty fillet required) to make the tabbing follow an easy angle instead of a hard 90. It ends up working like a shock absorber and keeps the bulkhead from working like a really dull blade on a shear and cutting (breaking) the hull.

I am not sure but I think the bulkhead is also supposed to keep the stringers separated when the hull panels flex in the forward section. By being glassed to the stringers on the side I think the loads get spread across the stringer area too. With the bulkhead broken out I think you were getting really high loads on the forward edges of the stringers where they attach to the hull so any cracks there would get worse.