If the sensor outputs 10bits in video mode , for 10bits 3x3 binning , the maximum value after binning is 0x3FE * 3 * 3 = 0x23EE ,
if so , it's impossible to explain why there is highlight overflow in 14bits :
viewtopic.php?f=2&t=2316&start=100#p17528
viewtopic.php?f=2&t=2316&start=100#p17534
i tend to think that single pixel ADC is 12bits , then 9 pixels are 3x3 binned (added) to 14bits , so highlight overflow may occur .