Guys, this may be a very stupid thought, but when we still don't have a solution, one starts looking in "unlikely places".
As we know, turning the throttle forward on this bike disengages the Cruise control.
Is it possible that as one is coming to a stop, one is inadvertently pushing a little on the throttle (turning it forward, same way one would disengage the cruise control), and this in turn is causing the engine to stall? Would explain why sometimes when one is coming to a hard stop, maybe leaning on the throttle grip, bike stalls.
Unlikely but just a thought.