Canon has started offering some sensors for sale, though not ones for "normal" cameras. Anyway, this means that there are some spec. sheets publicly available, which I have not seen before, and maybe some insights into Canon's technology can be gleaned.
https://www.usa.canon.com/internet/portal/us/home/explore/product-showcases/sensorsFor example, they seem to have about a four stop range of pre-amplification, which I think is done with variable charge in the transfer from photosite to capacitors at the sensor's edge. (At least, that is how it was done in some older Canon experimental sensors described in conference reports.)