I have yet to find a banking app that refuses to work on LineageOS. The only problem is if you root your phone, in which case you'll have to use Magisk to hide root from those apps, which also works fine so far.
Revolut is notrious in this regard. If memory serves, they explicitly check the build string for LineageOS and block the app if it matches. The workaround at the time was to build the ROM yourself with a new build name string.
Good to know. I'm using N26 and they work just fine in Graphene OS. What I do is I create a private space for the apps needing play services, which I keep locked most of the time. This acts as a separate profile and when locked, the apps including play services are completely off. My main profile uses only open source apps and no play services.
I actually called N26 (I'm a Metal customer with my own phone support) and asked will they support Graphene OS or no, and they said to me they will and gave me instructions what to keep in mind when installing the app.
This is the problem: it was a cat and mouse game always. I managed even strong integrity with keybox stuff and so on. Yes it is possible. But if you really need to do send money or e. g. want to pay with NFC, it gets rather stressful. Yes, I got everything working (Note 10 pro on LOS 23), but never longer than a few month.
I actually called N26 (I'm a Metal customer with my own phone support) and asked will they support Graphene OS or no, and they said to me they will and gave me instructions what to keep in mind when installing the app.