YES as you said it will work well for predefined auto mission ,but here my concern is whenever I want i can able to land the plane but not with predefined mission . why because my mission may end with any time (within endurance of plane) depending on the mission.
i have Suggestion for landing .
Landing Waypoint should be separate as below which independent to mission waypoint.
so each and every waypoint can change with different height and speed that model can fly for landing.
so aircraft can fly at any mode until execute the land command, when execute land command it will follow the landing waypoint and VTOL transition at transfer point to Quad when entering transfer point(Landing point) radius.
Note :this waypoint is auto generated based on plane speed and bank angle ,Stall speed .
like TAKEOFF mode in fixed Wing .when command takeoff it will reach particular height (predefined) and loiter over the home point without entering the Auto mode.
i remember that long back this feature also not available …Autotakeoff was part of mission only but now its independent with Auto mode.
so i think it can be improved in future.