\defaultfontfeatures[MonaspaceKrypton-ExtraLight]
{
  Extension=.otf,
  UprightFont=MonaspaceKrypton-ExtraLight,
  ItalicFont=MonaspaceKrypton-ExtraLightItalic,
  BoldFont=MonaspaceKrypton-Regular,
  BoldItalicFont=MonaspaceKrypton-Italic
}