Firstly, you cant use BC funds to repair lot owner property.
Everyone affected will have to pay their own costs, which means an itemised bill from the builder, or an agreement from each affected owner about how much each will pay (and the totals have to add up to 100%)
The next challenge I see is how to get everyone to fix their balcony.
I am unfamiliar with Tasmanian strata. But possibly there is a section of the act or a bylaw that says owners have to maintain their property. With engineers report in hand, insist that each owner has to repair their balcony. If there is push back (which invariably there will be) the BC may have to take it to the courts to get an order that says all balconies must be fixed.
It all hinges on an engineers or builders report identifying the issue, to satisfy the court