I just love that lower picture, HM! So illustrative. Any idea what alpha that is, and what the 'white' ?vortex? is which appears to start 'nowhere'?
Being well out of touch with modern aerodynamics like the ogive, has the 'stall' been re-defined for these shapes? Obviously there is no clear point where flow 'separates' since it is pretty well 'separated' at most angles and the classic 'nose-drop' and sudden onset of sink rate are no longer there. Do you know what the trigger is for the ultimate breakdown of the 'attached' vortex?