I think a common exhaust plenum feeding the 3 turbos would be the way to do it. Im not sure how the hot sides would like a rather slow individual pulsing exhaust. I have no experience with a single cylinder turbo setup, maybe is not an issue (probably not per video!) . can you fit them all in the length of the head? They would have to be very small to keep the velocity up but IR's would allow them to be pretty snappy boosting. These guys got 3 lbs out of 4 turbos....with lots of leaking exhaust..