I've recently added a "light pipe" mechanical cell to our library. I would have preferred to create it as a package cell, so it could be placed in schematic, and annotated to the PCB, but alas, the age-old problem of "if it doesn't have a pin, it's not a part". Since this part only requires NPT holes, I can't make it a package cell, so I created it as a Mechanical cell. Now, when I place it the design, it will not allow me to overhang the board edge, and unless they've hidden it in some obscure place, Mechanical cells do not seem to have the "allow cell overhang" check box available. So what's a person supposed to do when they have a mechanical part that is supposed to overhang the board edge by design, but the tool doesn't seem to support that?