you can run the second engine back up if you get in a real jam.
Everyone who has flown my triple with simulated engine out has become disorientated within two circuits. Practice in non-emergency time is the key to learning engine out flight.
I slaved the channels together, desensitized the pots for independent synchronization and put each engine shut back on a switch. I shut down the engine to a fixed 5000 RPM for reliability. Too much time at idle and the engine will not comeback up reliability and you will have a real emergency. It takes me about two hours on the bench including running the engines to set up the radio and verify that everything is operating as expected.
I have a Futaba and will dig up the details if you need or have difficulty.
At our field everyone stops to watch the crash when an engine goes out. A normal landing with one still turning is an ego trip.
Have fun.
Bill