Lol yeah right. Fat chance I would ever let them do alternative surfaces. Their brains are already exploding from using all 4 limbs at the same time.That would be 6, so no. Here's the excerpt, not to say that we do this now, but we have in some places.
"Alternative Surfaces
If at all possible, it is advantageous to allow the students to experience some simulated real-world situations. Riding on grass, dirt or gravel where available (and allowed) is encouraged if it can be done safely.
Potholes and Road Imperfections
Potholes and road imperfections can be included to impart reality to the exercise. Demonstrate to the students how bare(sic) their weight on the foot pegs at the same time as elevating their body slightly from the seat.
Be generous with your "thumbs up" and your smiles.
Start from a Stop on a Hill . . . "
No thanks