I ordered one of these just out of curiosity.
https://de.aliexpress.com/item/1005007232336060.html
Price today is 1.49€ and free shipping on orders above 10€. Not sure what price you see on the other side of the pond.
They work for cross-wound cones with a 3" / 7.5cm base. Smaller and larger thread cones do not work with this thingy (well, depends on the core diameter which on my cone is approx 1")
Could be a workaround and prevents "heavy weight" x-wound thread spools from spinning on the thread pin. That sometimes can cause tension problem.
Design could be a little better, IMO it could use a set screw to secure this thingy on the thread pin and the tube should the 3/4" or so longer so it would thick out of the hole on the top of the thread spool but anyway - it works as is but needed a little bending here and there.
Not that everybody needs one (there are other "options" too) but its a fairly cheap workaround and could be an improvement.
Just wanted to share this. 😉
Some quick pictures: