Global resizing for grace notes dynamics

[Karim Barkati]

Hi list!

I'm currently engraving a score using Lilypond, so first of all: thank you for 
your wonderful software!
In this contemporary score, there are many grace notes with one dynamic per 
note, so that having smaller dynamics on grace notes would definitely make this 
score look better.
Is there a way to specify globally a (smaller) size for grace notes dynamics? 

I wish Lily had something like this:
\override Voice.graceDynamics #'size = #'smaller
\grace{ a8\p [ gis8\mp ]}

For the moment, I think I would have to specify the size for each grace note, 
right?
\grace{
    a8_\markup{\tiny \dynamic p}
    [ gis8_\markup{\tiny \dynamic mp} ]}

Best regards,

- Karim Barkati