*** Okta Integration Inquiry for AngularJS & Java Play Framework Application

We are integrating Okta Classic Engine for authentication and self-service registration into our application, which uses AngularJS for the frontend and Java with the Play Framework for the backend. We have several specific requirements and questions:

- **Pre-Registration Validation:**

Our app requires users to enter their email, phone number, and a unique identifier during the registration process. We need to validate these details against our own database before registering the user in Okta. Should we opt for the Okta Sign-In Widget or the AuthJS SDK for implementing this validation step?

- **Deployment Approach (in case of a sign-in widget):**

       Given our pre-registration validation requirement, would an embedded integration or a hosted solution be more appropriate for our application? Does the choice affect extending the solution to support SSO in the future?

- **Third-Party Cookies:**

       From what we understand, an authorization work flow with PKCE seems to be the recommended approach in this case. Given that the third party cookies are going to be deprecated, are there any additional considerations to be taken into account?

- **Two-Factor Authentication:**

       Is it feasible to use the mobile number provided during registration for SMS-based two-factor authentication in Okta?

We seek your advice on the best practices for these scenarios, along with any relevant documentation or examples that could assist in our implementation.

Thank you for your support.