I made a copy of the bit that kept going missing (after it was found) 🙂

First iteration — I designed in the tabs but they were too long and thin, so I ended up going back to make them just over .5in in length and a bit wider, removed the tab at the back of the bit, then manually added margins to the tip and the back and removed the side margins:

Final iteration with fixed tabs — the tip took hours to figure out, it’s a combination of a stretched cone, a cone with parts subtracted from it, and a custom shape extruded upward then distorted into a helix:

Cut a 7″ piece of poplar:

Done:

After very carefully removing the shape from the block on the band saw and sanding: