I don't believe this is possible, but it would be nice if we can filter which system fonts are imported. Something similar to what can be done with custom fonts :
<font id="FONT_LARGE" filter="+,-.%:0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"/>
I believe lot of memory could be save...