Putting my bush lawyer hat on (it’s a wig, with corks) I’d say if the use by unauthorised people is being ignored, then the pool isn’t “fully compliant”. Its insurance coverage applies to authorised users, not the general public. If there was an accident, the body corporate – i.e. all owners – could find themselves directly liable for damages with no insurance coverage if it could be shown that they had knowingly breached their own rules.