I use FFR on my Oculus Quest 2. IME, text quality is more constrained by the res of the device, and I personally find it painful to read on my Quest - whether in FFR or Immersed - for extended periods. Others don't seem to have the issue, and people on HN have posted about working full-time in VR, so YMMV.

The question is about font rendering. Do they rasterize text into a texture, then draw the texture on a 3D plane in VR introducing artifacts at the second step, or do they rasterize text directly in 3D space using the view matrices?