Did you try increasing internal texture resolution? It makes text crispier. The framerate will drop, but it's tolerable for this use case. I find it very useful. There are various resolutions supported, this is the highest where increase in quality should be most noticeable:

$ adb shell setprop debug.oculus.textureWidth 2048 && adb shell setprop debug.oculus.textureHeight 2048

You have to start application after this is executed. To go back to original, you can reboot device or run this:

$ adb shell setprop debug.oculus.textureWidth 1280 && adb shell setprop debug.oculus.textureHeight 720