What data is sent through from AEP to DV360 Destination

We have a Google DV360 Destination. Whenever an Audience is activated to this Destination, we’ve noticed that there is no mapping step. What data from AEP is actually being shared from AEP to the Destination?

Our understanding is that no PII is shared with a DV360 Destination.

• We have multiple identifiers set up in AEP.
• Our CRM ID is set up as the Primary identity. This ID will only have a value for clients. Prospects will not have a CRM ID.
• Subscriber Key is another unique identifier.
• GAID, which is derived from the _ga cookie, a Google Analytics first-party cookie.

We do NOT have Apple's IDFA or Google's GAID set up.
We don't believe any hashed email IDs are being shared. Again, there is no mapping step that shows email addresses mapping. We also don't believe Phone Numbers are being shared for the same reason.
We don't have Adobe Audience Manager device identifier (AAM UUID) set up in the platform.