I’ve added a notch to the whorl of my student spindle. I make these from a 5/8” hardwood dowel, a cup hook, and a toy wooden wheel. Using a belt sander, I shape the ends of the dowel slightly; the top to accommodate the screw-in cup hook and whorl, and the bottom to make a point so it can be used also as a bottom whorl spindle. I read that beginners should also look for a spindle with a notch in the whorl to help hold the spun yarn in place. That is easy enough to add with two quick cuts with a small saw and some progressive sanding starting with 120 grit and working down to 400 grit. I had to test the new feature, as you do, so spun up some Shetland wool. The notch lines up to the back of the hook to help prevent the yarn from spinning around the whorl. I am past that learning hurtle, but I can see how this might help a beginner, so I’ll continue to add the notch.