For anyone else going totally crazy from this, I found it mentioned in another thread that standalone and VST3 versions of a plugin can look much different. Like most devs (I imagine), I primarily test in standalone, but it seems like there’s a big difference when it comes to fonts. I just compiled as a VST3, fired it up in Bitwig, and it looks great 
Mac standalone looks great, so it didn’t occur to me that the same might not be true in Windows (in fact, one of the things driving me nuts was how terrible my fonts looked in standalone compared to Visual Studio’s own UI text).
It seems like manually removing hints from the font with something like FontForge suffices, and then letting the VST3 host deal with the rest.
I’ve seen recommendations to use OTF instead of TTF for Windows, but this hasn’t mattered in my experience (and trying to transition to the OTF version of a font was very painful for me since the font size seemed to be rendered totally differently).