Surely the first question to ask is Does it require council approval
If it does before anything else this approval needs to be obtained. The Strata shouldn’t doing anything to an illegal structure except maybe removing it.
I’d also get a copy of the Strata plans and bylaws from the NSW Lands dept to make sure the plans you are looking at are the same as those registered.
I bought my townhouse 13 years ago and the documents provided to me by my solicitor were not the ones registered with the QLD gov and this only came to light over the last 12 months due to an Adjudication case. Not sure if the other owners doc are correct or not but the SM had the wrong ones as well.