I assume you refer to the module version of the custom payment method. I just tested the latest 1.2.1 and hit two issues:
- If I set more than one custom payment method, then I do not see any of the custom payment methods during checkout. There is a big box I can select and after confirming the order it just go to another screen with nothing and the order still in the cart.
- In back office I created 3 custom payment methods, then delete 1, then add a new one again, the thumbnail of the new custom payment method shows the one from the deleted custom payment method. Even I uninstalled the module and re-installed, after creating new custom payment methods, old thumbnails are shown.