No, in that way you’re mapping 20K levels to just 4096, so you’re not taking full advantage of the capabilities of the sensor. Or, quoting Jon:
Regarding your second objection:
Nobody here is underestimating the importance of dynamic range, for sure I’m not. But I think it is safe to say that dynamic range is much more important for LRGB than it is for narrow band imaging, as I mentioned above (“LRGB exposure in light polluted skys can actually benefit from low gain values”).
On the other hand, you can’t get rid of FPN noise by increasing the number of exposures, because by definition it is not a random noise. Dithering may help, as long as FPN is actually “fixed” (some sensors are affected by a sort of pattern noise that may shift slightly from an exposure to the next).
That said, I think we are way off topic here.