What it is: Remote evaluation for flags and experiments now includes a built-in "First Seen" user property, pulled from the amp ID table at evaluation time. Flags and experiments can target on this value directly, bypassing the cohort membership update cycle that makes new-user targeting unreliable. The property mirrors what's already available in local evaluation via Web Experiment.
Where: Feature Flags and Experiments
Who: All customers, including EUDC
When: GA. Available now.