since you already have Windows Hello for Business Cloud Trust and related Kerberos AD RODC objects set up, you've got a good foundation for additional authentication features.
Compatibility with Existing Kerberos AD RODC Object Typically, the Win 11 Passkey feature would work in conjunction with your existing Azure Active Directory and Intune configurations. Since you already have a Kerberos AD RODC object and Active Directory Connector set up for Windows Hello for Business, it's likely that you can continue to rely on these existing objects for implementing the Passkey feature.
I'd still recommend documenting and testing in a controlled environment, hope this helps!