I don't know factually if this is the answer to the question about having two switches on the exhaust side, but my guess is that since the engine is a spark/gasoline engine, the owner wasn't expecting much in the way of exhaust residue leaking from the engine area and blowing over the model in that area.

Myself, I would still have installed the switches on the other side, but the way this is, it's not as bad as it looks.


Ed Cregger