Based on, for example, spare change usage and recurring payments, there should be a better display of feedback when your desired “goal” is expected to be reached.
Also, the spare change saving feature actually encourages usage in order to save money, which seems a bit counter-productive to me. Perhaps there could be a reverse feature: Based on historical spending habits, if you manage to minimize expenditure, the savings should pass automatically to your vault. This probably works against Revolut business model though
For example, if your average restaurant consumption is xxx per month, if next month this is minimized by 20%, the savings should pass to your vault.
Also, split amounts should be better taken into consideration for spending habits.