On one occasion I had a Deuce go up on a single C6-5. It was a low flight, but everything was OK. I was using a nylon chute with kevlar shrouds, so I am sure that helped a bit, since the delay was about 2 seconds too long.
My first Deuce (two, actually) should be in the mail today, and I'm looking forward to building it! I've read in this forum that the Deuce will still fly to a safe recovery if only one motor lights... I'm half tempted to load mine up once and only hook up one igniter, just to see. Probably won't.
I haven't heard of anyone having a motor failure on a Tres yet, but with more motors, there's a higher probability, right?
We have quite a bit of data on the Deuce's Wild! on one motor and we're running at a 95+% success rate. Odds are good that you'll do fine, though with only one motor burning the delay will be a bit too long.
As for the Tres, we have no imperical data but my experience tells me that you would be *ok* if only 2 motors lit, from a stability point of view, but again the delay may be a tad too long.
If you only got one motor lit, the Tres would most likely be grossly under powered and may prang.
This spring I will be performing these very tests on the Tres.