\defaultfontfeatures[CascadiaMono]
   {Extension=.otf,
    UprightFont=CascadiaCode-Regular,
    ItalicFont=CascadiaCode-Italic,
    BoldFont=CascadiaCode-Bold,
    BoldItalicFont=CascadiaCode-BoldItalic,
    Contextuals=AlternateOff
}