Changing the appearance of the number of Clef Modifier

How to change the size or shape of the small eight (or whatever number) appears in the ClefModifier.

\version "2.24"

{
  \override Staff.ClefModifier.font-shape = #'sans
  \override Staff.ClefModifier.font-series = #'bold
  \override Staff.ClefModifier.font-shape = #'italic
  \override Staff.ClefModifier.font-size = #+4
  \clef "treble_8"
  c'
}