If all the owners have smoke alarms and the Owners Corp pays for their installation and maintanance, then it’s the same as having them all paid for individually (notwithstanding differences in unit entitlements). This argument is another example of the disconnect between the concepts of ‘us’ owners and “them” the ‘strata’ or owners corp (which are the same thing).
However, somewhere in the dim recesses of my mind is the concept that if the hard-wired smoke alarms connect to a common or chared control panel, the are common property.
Next, let’s deal with the idea that smoke alarms are a safety measure for everyone and not just an inconvenient luxury for all but those who set fire to their homes.