I am using Passport for my MEAN stack-based app, that makes use of several APIs that require several OAuth tokens. Because logging in and out causes too much overhead, I am considering to put serialized session data in a Redis store then swap back and forth between existing sessions.

So my question is, is there a way to programmatically extract and/or replace passport data ?

You could try storing the information in MongoDB by using serializeUser() and get it back using deserializeUser()?