For our application, we’ve successfully implemented a custom login flow using actions to detect whether a user needs to be prompted for an additional factor, and which factor they have selected.
After the user enrolls, their first use of the otp entry form appears with our styling as expected. They are then allowed in to the rest of the application. However, once they log out and back in again, the styling is not applied, and there is also no way to navigate back from certain parts of the form.