There are two kinds of oil used for outboards. You almost certainly have the lesser of the two. The verdict is still out on the lower quality oil. Outboards work very hard but they also are generally well cooled.
I'm running the dirt cheap Walmart brand outboard oil in my 66cc engine, no worries for me but to each his own. These Chinese engines when stock are low power output but if you have an expansion pipe and run at 7500rpm all day long I could see some peace of mind from spending more on the oil. The engine costs, what, $90? I can't see spending much money on oil. It's not like you are protecting a very expensive and high output Rotax engine.