Since you only care about the extreme stress in the model, you can solve with all blends removed, then add the blends back in on the few edges near the region of high stress.

Ductile materials have a material property called Elongation at Break (or just Elongation). If you turn on plasticity in the material model, plastic strain will develop in elements that exceed yield strength.  Plot Total Equivalent Strain (elastic+plastic) and compare that with Elongation to judge failure.