FacetID equivalent for WebAuthn?

Is there anything similar to FacetID available for WebAuthn?

How is a multi-domain deployment supposed to work with WebAuthn? And by
multi-domain I mean domains that don't match: example1.com and example2.com.

One solution that was suggested is to always redirect to the IdP, so there
is not need for multiple domains. That might work for login, but when
WebAuthn is used as a re-authentication challenge then a full page redirect
becomes very difficult to implement, especially for an existing application.

Anyone else running into this limitation?

Thanks,
Marius