User ID posting to Zoom Events Registeration API

Hello All,
We need your support in 2 topics ;

  1. User Identifier (User ID):

We need to track users using a unique identifier (as illustrated in the table below). During our review, we identified the ‘source of registration’ field, which appears in both the Zoom Registration API (used during user sign-up) and the Zoom Attendees API (used to collect event interaction data).

a. Could you confirm whether we can use this ‘source of registration’ field to pass and track a user ID across Zoom Events?

2**. Event Tagging:**

For accurate reporting, we need to tag events with Brand and Therapeutic Area (TA) names. In Zoom Webinars, this was achievable via custom tags. However, based on my recent reviews it seems that Zoom Events may not support custom tagging in the same way.

  1. Is there a way to implement or simulate custom tags for Zoom Events and individual Sessions?

We’d appreciate any guidance or alternative approaches you can offer to help us achieve these requirements.