I used to wrench on these bikes a bit back in the 70's. If my memory is correct, it is not a simple job to remove the oil injection pump and run premix on the TS Suzukis. The oil injection pump supplies oil to the magneto side main bearing, which may not get a proper oil supply on premix. (If there's some vintage Suzuki nut on this forum who recalls otherwise, feel free to refresh my memory.) I've seen people get away with it but my thoughts are: why would you do ANYTHING to compromise the oil supply to ANY critical part on a two-stroke engine?
My experience: The oil injection systems on these bikes are very reliable if adjusted properly. Run good 2-stoke injection oil in it and leave it alone.
If you're really worried, some guys used to wire the pump arm wide-open so the engine is getting full pump output all the time. The engine will smoke a little more, might foul a plug once in a great while, but other than that it should be OK.
Mike