DR has more to do with the design of the sensor circuitry away from the pixel. The analogue to digital converters, for example. Interference in the circuit from other circuits or the camera. DR is all about quality.
nice platitude ...
if everything at the sensor/photosite level works optimal then the ADC is the factor that determines the achievable DR.
but i guess there is room for improvement on the sensor level.
for example the filters can be improved, the substrate can be improved, coatings can be improved, the fill factor can be improved, gate structure can be improved.
all things that affect quantum efficiency, well capacity.