It depends on the year model. The older Rotax 4-TEC motors could use synthetic. The supercharged motors could not because of the ceramic slip washers coming apart, causing damage from a lack of oil because oil ports would get stopped up. The synthetic oil is too slippery for the clutched superchargers.
They have since stopped using that set up and using a steel washer. I read an article last season that said they are now using mineral oil.
I see you have an 08 model 215 hp. I use synthetic oil in all my 90 model 787cc motors. But, if I owned the newer, supercharged 4-TEC, I think I'd stay with regular mineral oil.