Tundra is a more experienced than I in that area. He had an incident or two in his Antares as well as one in the Tundra toy. I've been lucky so far and the closest I've come to an engine failure is having to hand prop
I haven't had to make a forced landing yet, but I've had a few short engine failures followed by restarts, and at least one precautionary landing. Surprizingly I've had far more trouble with O-200 in my 150 that I ever had with the Rotax 503 in my ultralight. Maby not surprizing, the Rotax was brand new, the Continental is 40+ years old, and I've flown it 3 times as much.
1. Flooded the engine in my ultralight at 8,000AGL, lots of time for a restart. No in-flight mixture control.
2. Strange vibration during climb out caused me to do a quick 180 and limp back to the airport at minimum power in the 150. Resulted in a major overhaul: 2 cracked cylinders, crank journal out of round, center main bearing slipping, carb generally worn out, 2 different styles of pistons (one of which hadn't been made for 30 years).
3. Grabbed mixture instead of carb heat on down wind once. Only took a couple seconds to figure that out and fix it.
4. Carb heat scat hose full of rain water killed the engine during a downwind departure once, (thought I got it all dried out on the ground, there's a drain in the low point now. :p ) Engine restarted as soon as I went back to cold air.
5. REALLY bad carb ice a couple times caused a complete loss of power on climb out for a few second untill carb heat cleared it enough to recover.
So yeah, a second engine that'd at least stretch the glide a bit sounds like a very nice thing to me.

Phil