HIya @Weirdo – stepping in for Toku, as I got an answer from engineering I can share.
This does seem intentional.
From the code, there is “radius needs to be divided by 2 due to the Figma radius effect being effectively double”
What we’re saying is that a value of 30px in Figma is equivalent to 15px in CSS. The reason annotations say 30px is because they’re not CSS-specific.