While I agree that down sizing the neutral is not worth it in most cases I would have to say that you have bigger problems than an undersized neutral in your apartment complex. Third order harmonics, the type generated by computer power supplies, do not multiply in 240/120V single-phase systems as they do in 208/120V systems. Also, oversized neutrals mitigate heating problems. They do not cancel harmonics in the system. They merely create the capacity to handle them.
