commem
Try this link
https://www.nsw.gov.au/sites/default/files/2022-03/common-property-memorandum.pdf
generally it needs to be voted and added as a bylaw, but I have used it in situations where opinions differ
Your biggest challenge will be winning the opinion battle. Everyone has an opinion, but there is only one right. As you know, that does not always prevail if the negatives are the loudest.
It depends how far you are prepared to take this issue. If someone does not back down, then NCAT could be a possibility (though thats a last resort)