I’m not sure what the benefit of categorising a top-up to be honest, as you’ll categorise that money when you spend it on something if I’m missing something there though, let me know!
But it definitely does make sense for refunds, as ideally, you’d the refund to be credited to your Target for the same category as the one that the original transaction was assigned. Fortunately, Monzo are looking for ways to enable this -
By the way, if you think there are categories that are ‘missing’ please do share them, Monzo are due to review the categories, after the current accounts launch & I expect more will be added…