I have more or less understood how it works but I think I must miss something.
Here, I'm selectioning the Start and End face adresses :
Start face

End face

Then, I'm more or less sure than the FVF size is 48 because it works well, I tried others (20...52...100 etc.), 48 is the only size I get a result.
The models I get

But in Pointcloud, here is what I have first

Just for test, I increased the vertices count and here is what I have and what I what (but even, the model seems not complet)

Can you tell me what am I doing wrong please ? (I don't mind the UV for now)
I attached the file I'm using, you can see the value on the images.