(...)

I guess a larger bias could mean stronger signal for the amplifier that comes after the DAC that clamps black level. But if you raise the bias too much, you are forced to lower the ADTG gain, and this will introduce quantization noise. Probably there's a sweet spot somewhere.

Indeed again, as I said there's a relation between all these parameters.

The optimal config is easy to gess, on the paper, but hard to implement. I'm stuck at this point right now.

In a scientific view of all of this, the best choice will be:

_. the lower pedestal value where RON + FPN sigma is contained therein

[current original Canon bias is too high, because have to fit with all ISO; for example with 5D2 it could be N-times lower for ISO where gain <1 (in my graphic just up you can see it could be ~10x lower)]

_. the more closer analogic gain than 1

[but in real world and for usual photography, gain has to be <1 to equiv low ISO sensibility, so we should use a matrix for all ISO/gain/bias optimal values]

_. the lower digital gain

[in fact if we could have a matrix for all ISO up to gain <1 where DG is null it will be optimal, as it done for audio signal]

Please not that I ever do most of these optimizations in post for my work, I could demonstrate/detail/explain parts if need.