Wrt stacking order of inset shadows, @smfr wrote: Maybe the inset shadow never overlaps the stroke, but conceptually I'd expect the inset shadow to render below the text stroke (but above the fill).

The inset CSS property is a shorthand that corresponds to the {{cssxref("top")}}, {{cssxref("right")}}, {{cssxref("bottom")}}, and/or {{cssxref("left")}} properties ...