[NTG-context] superior numbers for footnote numbers?

[Jörg Weger]

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.