Hi Alan,
As I was thinking about the design of the HM-26/27/32s, I realized that in fact the valve control is near the end of the key: about an inch in from the front end of the white keys and right at the very front end of the black keys). The ratio of movement of the key to the movement of the valve approximates 1 to 1.
Maybe this is why I have trouble bending notes using the “slightly depressed key” technique.
Regards,
Tom