An airfoil that will never stall, no matter the angle of attack

Or not enough airspeed, which is the most common stall condition real pilots face (caused by a variety of scenarios such as too much altitude, runway approach too slow, etc).

What does the list-to-drag ratio versus AOA curve look like?

An airfoil describes the stall characteristics of the wing.

Camber, chord, edges, angle of attack .. these are all described by the airfoil and are key to flight control, including stall handling. How an airfoil gets itself out of the stall state is of great interest to designers.

Airfoils which utilize the Magnus effect (as in this case) do have different stall characteristics. Its not incorrect to refer to the airfoil in that context.. a bit like calling a soccer ball not just a sphere but also a wing, too, which in fact it is to most airfoil designers .. ;)

Kind of reminds me of a lot of ekranoplan designs.

Absolutely not. To glide well, you need big ol' wings. There's a concept called aspect-ratio, which is basically the relationship between the wingspan (left to right) and wing chord (front to back). High AR = better for gliding. Conversely, and in the case of the mini-PW, when you have virtually no wingspan, you aren't going to glide very far. We affectionatly referred to power loss as "brick mode".

The website hasn't been updated in a while, but I assure you that development is still going on.