The default primary metric is set to End User Response Time (EURT), but you can choose between EURT and Visually Complete Time (VCT). Once the primary metric is configured, the Controller UI dashboards, summaries, and charts will automatically update to show trending data for that configured metric. This allows you to view the EUM event timing that is most relevant to your business needs.
You can set the primary metric to EURT or VCT. The default primary metric is EURT. EURT tracks the total amount of time for all content on a web page to be loaded. VCT tracks the total amount of time for all visual content to be loaded in the viewport. To see how EURT and VCT are calculated for SPA pages, see SPA2 Metrics.
The primary metric is visible across several dashboards, charts, and summaries. The following screenshots are examples of primary metric visibility when configured to VCT.

To configure the primary metric, go to Configuration > Instrumentation > Settings.
For SPA2 applications, configuring the primary metric causes base page events to be sent on navComplete; previously the base page events were sent upon page load. This may cause slow performance, and you may want to disable the primary metric.
To disable the primary metric, add the following flag in your JavaScript code:
config.enablePrimaryMetrics = false
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