Hey there, thanks for this!
We’re exploring this in design at the moment. At our launch events we did some user research to better understand people’s needs around tipping, and @eoghan is working on some ideas that could help.
In the UK - we don’t tend to send notifications when transactions settle, but could potentially for when the amount changes for certain categories as you suggested.
We’re also exploring suggesting a tip amount in the original notification, and letting people tell us how much they tipped via card (after the payment), so we can proactively adjust the payment amount (and their balance) before it settles.
We need to be careful here to not make things more confusing if the tip is included in the initial payment, or if you tip with cash - but there’s definitely and opportunity here to do something really useful and slick.
The main things I’d love for us to help with are:
Not thinking you have more money to spend than you do, due to tips not settling for a few days.
Understanding that if you have a budget of $100 for eating out, that you actually have ~$80 when you factor in your typical tip amount.