Tags is indeed a great step forward to help the organisation of your spending but my initial feeling was that the experience of creating tags is quite fastidious and not really pleasant compared to categories. Tags are hidden in the note section and doesn’t have any validate action to save it.
Why not transforming categories into tags? You have a pre-selected selection of categories but you can add custom categories. Why not also have multiple categories per spending.
As an example I still don’t know where to put all my internet subscriptions like Spotify, Netflix, … It would be amazing if I could just create a new category called subscriptions instead of going into nots and add a tag on top of a non ideal category.
Perhaps there is future developments in the app that I’m missing but for now, tags doesn’t make sense to me.