@Pradeep_Kumar_Srivastav Quite an interesting question there. It has a number of challenges though as we drift away from cookies and in the AEP world since AEP has a broader view of the world (i.e. events beyond just web events). Also, since AEP links identities such as ECID with each other, it forces us to rethink if that is a new visitor just because we see a new ECID.
Because of this, you might want to kick around other options, such as: