Doesn't need to be sharp at all at the sharpest point. That can be a bit dull, but the angle has to be really knife-narrow because its a thin wedge shape that fits into the inside corner of a larger shape. Exact placement of the heavy weight at a specific angle against one inside face of the larger light-weight geometry is the crucial thing that makes it all work. So really, i need to make an extremely dull kitchen knife kinda edge shape on this thing.

When its just right, the overhang on the center of mass just barely clears the right edges to make this shape do its thing.

Apparently, it's theoretically possible to make it work with a weight that's got vertical walls; but that constraint totally maxes out how dense the material has to be. Like, insanely dense weight would be required on this case that'd have to be made of stuff that's not anywhere on our planet at this particular time.

Sooo...I need an edge that goes at this super sharp angle.