Just for fun, I have added a new shape to my symbol node: Squircle.

A squircle is like a rounded rectangle but without any straight edges:

https://en.wikipedia.org/wiki/Squircle

Squircles are commonly used in app icons (Apple uses a precisely designed version) and are commonly seen in the real world as plates: they have no sharp corners, pack in the same space as a round plate, but hold more food.

There are two different mathematical definitions of a squircle, and many subtle variations in different computer contexts. My squircle is extremely simple and, I think, closely matches the mathematical squircles.

The attached demo shows the difference between a squircle and a rounded rectangle.

Enjoy!