Currently there's no way to do this. A practical problem is that most people would want to review the flats before using them. and to be honest, most people cal their data offline after they get it, even though it means downloading the cal framed (including flats). That notwithstanding, ACP does not have a way to automatically apply dusk flats to the same night's light images. Do you have a rotator? Is that why you need "fresh" flats each night (different PAs)?