Fabian, thanks for taking care of this and for looking up the upstream bug. I'm just not sure how using the TTF version of a font could fix the OTF version.
Looking at the discussion of the upstream bug it looks like these folks have not more knowledge about fonts than me, so I researched how these ligatures could be removed without having original source files. Lo and behold, it looks like I have found a way and fixed variant Regular already. Tomorrow I plan to apply the same procedure to the other variants, triple-check everything and then make a pull request upstream. Markus
