THE SM WORKS FOR YOU THE OC
and so if you want to hold an EGM to reduce the SF levy do so and so long as you pass a valid motion to that effect you tell your SM to levy the new rate.
The SM doesn’t have any choice unless they take you to conciliation and adjudication to get the decision overturned (even if they are correct which I doubt) and for this they would have to spend their own money (NOT strata funds with no possibility of a refund from strata).
Think of the SM as the Strata Administrator doing the bidding of the OC or EC who make all the decisions.