I see two key differentiating characteristics of macro-prudential policy: first, macro-prudential only addresses significant systemic shocks, not idiosyncratic day-to-day shocks; and second, macro-prudential has a stabilisation role (albeit a secondary one) as it seeks to moderate cyclical extremes in credit growth and asset prices. Thinking about where the micro/macro-prudential differences might be reflected in a revised Act, the first is in objectives.
Under such circumstances, conventional monetary policy is ineffective because it involves operations with short-term government securities which, by paying a rate close to zero, become quasi-money and therefore the central bank cannot supply liquidity effectively through open market purchases.