In one of their videos [1] the mast can be seen vibrating at a high intensity. There is for sure lots of tension in the material produced, I wonder how durable the masts are. I have the feeling they would instantly break during a storm.
Wind turbines have pitch control to reduce the speed of the rotor and blades. This allows wind turbines to survive most storms. I don't see an equivalent control mechanism with Vortex Bladeless masts.