The Raj Hamsa XkAir is an ultra light. Because it is an ultra light it is not subject to most of the requirements of a certified aircraft. Ultra lights are also by definition very lightly built and thus have a sad significant history of inflight structural failure.
With respect to the dangers of an opened cabin door coming off in flight and damaging the aircraft I would suggest the instances of ultra light failures do little to inform with respect to that risk in certified aircraft. That being said the case for handling an open door may need to be different in Ultra light.
I personally refuse to fly in ultra light aircraft as I am not comfortable with the lack of a rigorous process to ensure design and construction safety. Since I am not familiar with UL operations please note my comments regarding the appropriate actions for a cabin door open in flight are restricted to certified light aircraft.
With respect to the force landing case I teach my students to if practicable to unlatch the door prior to touchdown, emphasizing that this must not be done at the expense of flying the aircraft.
I also tell my students that in the event of a forced landing in a retractable gear aircraft, the landing should be done gear up unless landing on a runway is assured.