The switch is one of the weak links in your on-board electronics. Switches can fail due to vibration, for example. So many of us use two switches in parallel. For example, I have one battery. I solder two sets of wires from the battery. one set of wires goes thru a switch and on into the receiver. Same with the second wire (thru a second switch and on to the receiver). When I get ready to fly, I turn sw "A" on. make sure the surfaces move. Then I turn "A" off and switch "B" on. Make sure everything is working. Then I turn switch "A" back on and fly. Now I know if during the flight one switch fails, the electricity will flow thru the other switch and all will work OK.

Gasoline engines are probably harder on switches than glow engines (harder vibrations).

You can also use two batteries and gain some redundancy also.

Long ago, people would actually use two receivers also. But this has faded from use since the receivers are so reliable these days. Although the new JR 2.4 gHz receivers can be set up this way.