Configuring double button press

Mach 1 Pro:

If I double press the light button, it toggles the flashlight.

If I double press the start/stop button, it launches the ECG app.

If I double press the back button, nothing happens.

Can I configure this to launch the stopwatch app or similar?

Under Menu > System > Hot Keys, I can configure what happens when holding Start, Back, Down as well as four additional two button combos.  However, I haven’t found any way to configure what happens when double pressing the back button.  Is this not possible?  Seems like an oversight.  It’s kind of ridiculous the number of menus needed to get to basic clock features that use the physically etched start/stop/lap controls.