I use the toupcam driver for two CMOS cameras, a 12bit Meade DSI IV color and a 14bit G3M178M mono.

When I do 1x1 binning exposures they go into saturation at 4093 and 16383 ADUs, as expected.
However, when I do i.e. 2x2 binning, I see the same limits, where I would expect them to be at 16372 and 65532, four times higher.

As I see the effect with KStars and CCDCiel as clients and also with two different cameras I would like to blame the driver.
Did I miss anything?