I took EldeTabernas's lovely "lip" design and narrowed down to two more sizes. His original one is the 80mm and I added two skinnier cousins, 70mm and 50mm.
For each size, I added a latch. Some bikes don't need it, but some bikes, like my wife's, have extra weight pulling it out of the clip. A latch fixes that issue nicely.
Now I have more floor space; floor space for more 3D printers. :)