Sorry 30 years as a certified mechanic and working in shops my life I have seen the valves cause this. They can hold enough to stop a rotor from turning by hand but you could put it on the ground and drive it until it ignites the pads from dragging.
You may be right but it's not from the TYPE of device or how it works. This is caused by things like corrosion, rust, and other malfeasance plugging up the switch / piston mechanism. This is a piston operated switch. It is not a valve.
