The issue isn't with NFC. It's passing the Play Integrity check that app developers optionally can use to prevent devices that don't pass the check from running their app, or remove parts of its functionality. IIRC I don't think any custom ROM's can pass the check. So you might be able to pay via NFC with a banking app if they don't implement the Play Integrity API. For Graphene's thoughts on the matter (2024):
>>acheon+U9
GrapheneOS community manager here: They weren't using Play integrity and we were able to work around what they were doing, so Revolut should work again. They can decide to use Play Integrity in the future, though.
>>lollob+Fa
Revolut currently works fine on GrapheneOS. If they decide to adopt Play integrity, it won't work unless they whitelist GrapheneOS, which banks have started doing.