The icons for the different shapes don’t really make a lot of sense. It’s not really obvious how some of them work and many are quite unlike the actual pattern (which you have to scroll down to see on mobile).

Also Cahill–Keyes M, which I’ve never heard of or seen before, is described as “the classic M”. That’s not really helpful.

6.95 or point my LLM at the site and copy the simple idea.

Some interesting comments https://news.ycombinator.com/item?id=49093845