Thank you reaction
As mentioned on Twitter, although the new thank you feature is cool and personal, it's not something some other UK providers aren't doing (Monzo has the thank you emoji feature for example)
A thank you GIF you can set as an instant thank you message as soon as someone pays you would be nice, especially as everyone is so keen on GIF reactions nowadays. The popular Ducth Payment App "Tikkie" uses this feature and it's one of the main reasons it is the most used payment app in NL.
Push Notifications
As a CRM exec who is constantly finding ways to improve the customer journey, I would recommend more behavioural targetting on this one.
I often receive a PN about an update after having already downloaded the update so it would maybe be a nice one on this (if possible) to use a decision split in your comms journey based on application version. You could send the update PN to those that have the old version based on their profile application attribute and for those that have updated it you could maybe send a PN with something like "You're halfway there by downloading the new update. How about you test it out for yourself?"
Also utilising Rich Push Notifications (w/ imagery) improve CTOR.
Hope this helps 🙂