I always set neutral control surfaces and idle. I have had a plane go into fail safe before. When I got it back I was able to keep flying. Had it killed the engine I would have lost the plane or at least set it down in a bad spot. This was however a 60 size plane. If I had something with a DA-150 I would let it kill the engine. I have heard of people setting a slow turn with slight up elev. The way I fly the plane is inverted or knife edge a lot of time. This setting would stick it in a hurry. If your a sport flyer this may be OK. When mine went into fail safe it came back in less a second so it would not have been a big deal either way I guess.

David