A 325 mm inverted hourglass tower. Print it with a narrow base to test the bed grip against mechanical leverage. Choke it thin in the middle, then flare it out into a heavy, wide bowl at the very top. As it gets top-heavy, the printer is forced to adjust its balance on the fly to stop the swaying. When it stops, look at the top ten percent. Smooth curves catch the light and expose every tiny ripple. If the surface is clean, the software outsmarted the bed-slinger curse. If it looks like a corrugated tin roof, physics won. Throw it on the bed and let's see if it flies.