explainer: https://github.com/fserb/canvas2D/blob/master/spec/text-modifiers.md CSS currently support more text modifier that are not supported in Canvas Context 2D. We have discuss the potential to support in canvas and received approval from Jeff Gilbert in meetings and webkit (https://github.com/whatwg/html/issues/5617#issuecomment-641103995) I am filling this implementation bug for webkit to support it in the future.
<rdar://problem/77587455>