At the moment if a user has a Gift Aid declaration it seems all future donations will have the box ticked by default. If someone then make a non gift aidable donation, such as donating some collected income or legacy it has the potential to be incorrectly claimed if the users fails to notice or even realise what is gift aid eligible and doesn't untick the box.

Having a feature that says certain approaches can never be Gift Aided would be useful. I know this exists already in other chartiable CRMs