Hi Tom, In my opinion all gas engines should be equipped with electronic kill switches. I have four gas planes and all have one installed.
This is one feature I personally think all gas plane owners should install. They are relatively inexpensive and a great safety feature. As far as only having one on your trim, what if the engine vibrates loose and killing it with the trim is not an option,...........Theres just to many reasons why a kill switch is a good idea for your gas planes..................G/L
Chuck