People in Microsoft Viva – Putting people at the center of the employee experience.

I see some applications for large Sales Operations teams to begin to manage information/profiles of the sales team members. Where can I find information on the extensibility of the individual's profile? Am I limited to a specific set of fields? Can I create custom fields? How does People integrate with Amplify? Does it help me create audiences that can be targeted / analyzed by Amplify?
The new features of Viva seem to create the ultimate Sales Enablement suite. Very excited about this, and would love to see a Microsoft on Microsoft example that shows how you use Viva for onboarding, education, communication and listening in your own Sales team.