The color range selection is always present. It does not change or disappear for certain encoders.
There is always a possibility for "headroom" and "footroom" in a limited color range. It is just labeled like this for 8-bit resolution.
For 8-bit the range is: 0-255 (16-235)
For 10-bit the range is 0-1023 (64-940)
Actually I could remove these values to avoid confusion about it.
I have to admit I am not sure what it means for "ProRes". It is just a necessary technical requirement and I just allow the user to change this setting. And yes, it was absolutely intentional to set the value to limited by default.