If you want a smooth animation between two values of a corner radius (eg a button going from 32px radius on default to 16px radius on hover) the smart animation will work only if you don’t use a number variable on your corner radius…
This goes against the use of tokens for a clean system design.
Here are two screen recording showing the issue, i used variables for radius on the first one, and classic values on the second one.
(GIFs are slow but you see the problem)
