which undoubtedly makes it harder to control That's a problem for the software. Divided over the number of proposed units, the development cost is about zero.

which undoubtedly makes it harder to control That's a problem for the software. Divided over the number of proposed units, the development cost is about zero. The mass of the zeros and ones is also nearly zero. What it saves is moving parts, actuators, and driver circuits, all of which have a mass and cost per unit. !!! I make a guess on how it operates here, I think it's good, but don't take it as gospel !!! I didn't see it spelled out, but I theorize what they do is modulate the thrust of the single motor by the wing's rotational position to tip the entire object causing it to trade some vertical thrust into lateral thrust. Given that they already had to have a micro controller and a variable speed motor driver for the motor, the incremental cost in mass and dollars is zero.