Last I checked I couldn't set full hinting. And for GTK4 programs I even had to set a hidden variable in a ini file[1] to make it respect my fontconfig setting for hinting.

Apparently it is supposed to be on for low DPI screens. I would count mine as low DPI (even my laptop is only around 150 DPI) but I still need to set that manually.

So no, GTK didn't keep the font rendering settings I care about, and is actively hostile in trying to ignore them even.

[1]: https://wiki.archlinux.org/title/GTK#Text_in_GTK_4_applicati...