When it comes to identifying users across sessions, you have the option to leverage the Customer ID, which is an ID you provide when joining the meeting that can be used as a custom tracking ID.
Regarding Persistent ID, it is similar to user ID but persists when switching between breakout rooms and the main meeting. Since a breakout room is actually a distinct meeting instance under the hood, a given user will have a different user ID when they move between breakout rooms and the main meeting
