@ Bur : you were right :) My memory is some false :)
In Amapi
In Nurbs Mode you can Stretch / Extrude with just draw "the green line" and the red nurbs surface is automatically dynamically drawn at each new move / clic point :)
But I suspect that Polygons are under for screen drawing (you can see edges ;)
here a "circle" selected for extrude / Stretch (in the same time)
Stretch = vertical move
Extrude = horizontal move
Green line is the active path drawing between each clic or move of the mouse