No Stem Darkening - Font.conf?

Good afternoon,

I've used stem darkening with FreeType on Linux many times before, by enabl=
ing an environment variable like so:

FREETYPE_PROPERTIES=3D"cff:no-stem-darkening=3D0 autofitter:no-stem-darkeni=
ng=3D0"

I was wondering if there is a way to enable this through etc/fonts/conf.d? =
Basically, I want to enable stem darkening on one specific font only. This =
is a .conf file I've succesfully created:

<?xml version=3D"1.0" encoding=3D"UTF-8"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<match target=3D"font">
    <test name=3D"family" qual=3D"any">
      <string>Inter</string>
    </test>
    <edit name=3D"hintstyle" mode=3D"assign">
      <const>hintnone</const>
    </edit>
  </match>
</fontconfig>

Now I want to somehow get stem darkening in there, so that it only gets ena=
bled for the font "Inter". Is this possible?

Your help is greatly appreciated!