[NTG-context] superior numbers for footnote numbers?

Better equipped opentype fonts offer so called superior numbers as an opentype feature. Those are special smaller figures for “superscript” (opentype feature “sups”) that are not simply scaled down versions of the normal figures (be they oldstyle or lining) you are normally using. Scaling down is as far as I understood the default way context is using to generate the numbers for footnotes. Is there a way to define the use of unscaled superiors according to the fontsizes of body text and footnote text instead? Greetings Jörg PS: I am using for serif the “Linux Libertine O” family (installed as OTF and invoked by the included mkiv simplefont mechanism) which has the “sups” feature.