Something else worth looking at: the slug font renderer[0]. Sadly it's patented, but the paper[1] is there for those of you in the EU.
Any alternative solutions for the problem of GPU text rendering (that are not patent infringing)?
You can always render the text to a texture offline as a signed distance field and just draw out quads as needed at render time. This will always be faster than drawing from the curves, and rendering from an SDF (especially multi-channel variants) scales surprisingly well if you choose the texture/glyph size well.
A little more info:
https://blog.mapbox.com/drawing-text-with-signed-distance-fi...
MIT-licensed open-source multi-channel glyph generation:
https://github.com/Chlumsky/msdfgen
The only remaining issue would be the kerning/layout, which is admittedly far from simple.