You can use the contactless payments supported tag when searching the GrapheneOS banking app compatibility list on GitHub. https://github.com/PrivSec-dev/banking-apps-compat-report/issues?q=is%3Aissue+label%3A"contactless+payments+supported"

This is incorrect. GrapheneOS supports NFC, and works just fine with NFC-based payment systems. Google Pay is an exception, because Google specifically chose to disable it on any device that isn’t whitelisted by them. Other apps, such as Curve Pay, PayPal or banking apps with a built-in NFC payment feature work without issues.