Workaround If the ad-request executes before Brand Metrics sets the targeting-key.
Using a persistent user ID to aggregate exposures cross-device and cross-platform and storing it in the Brand Metrics backend.
A flyin survey triggered by GAM logic
Google Ad Manager / Xandr integration which automatically sets up Brand Metrics measurements from the ad server.
Per-measurement Survey Line Item
If you want to run individual line items per measurement (with in-ad survey delivery)
DMP Integrations
Create cohorts/audiences in your DMP by user relationship to brands