OurKTM 690 Enduro Luggage rack SD (2019+) uses two-piece triangulation design to deal with the vibrations and oscillations which are fatal for most racks. This way, great deal of these forces is soaked and not transferred to the frame (actually to the tank and tank bolts). This works great for soft luggage. Over the years, we perfected this system and it is very durable and efficient.
Keep in mind that top case can be used only on road. Off-road used is strongly discouraged, as added stiffness is not ideal feature for off road use - all vibrations and oscillations of the rack (and luggage on it), would be transferred to the frame (actually, as mentioned before - to the tank and tank bolts).