Comment by _Microft

What do you mean that their concept might not work at all? They have flown several iterations of their prototypes already but maybe you have something different in mind, e.g. doubts about the possibility to scale the concept up?

Here are videos of recent test flights:

https://www.youtube.com/watch?v=0idI3sJJKZw

https://www.youtube.com/watch?v=SqMEFdbuzQY

https://www.youtube.com/watch?v=jqvMXoVZfDw