Rule reminder
'Non che' + subjunctive is used to deny or correct a possible mistaken inference. It means 'not that...' and is followed by the subjunctive: 'Non che sia impossibile, ma richiede impegno' (not that it's impossible, but it requires commitment). It presupposes that someone might think X, and the speaker corrects: 'It's not X, it's Y.' This construction always implies a contrast and is typically followed by 'ma' (but).
Which mood follows 'non che' in standard Italian?