https://bugzilla.redhat.com/show_bug.cgi?id=1545149
--- Comment #16 from Nikolaus Waxweiler madigens@gmail.com --- It is possible that this is a bug in FreeType, you may want to send a mail there (https://www.freetype.org/contact.html) and point to this bug report.
On the subject of "removing the ability to get sharp stems": I can see your point, but sub-par autohinting can impair reading just as well by making text look very uneven. There is unfortunately no silver bullet here. Actually, there is no way for a user to tell a font how she'd like the rendering to be. Neither TTF nor OTF hinting have the notion of user adjustability (OTF maybe more so than TTF, but nothing of that is implemented in FreeType), what you see as an options in FreeType/fontconfig are misnamed switches and the choice you get is largely incidental. The thing to keep in mind is that there is a lot of familiarization baked into font rendering discussions, i.e. if you surround yourself with mscorewebfonts and DejaVu and crank hinting to full, the rendering in the shot above will stick out like a sore thumb -- and vice versa.
fonts-bugs@lists.fedoraproject.org