Enhance custom data tracking section for Azure Functions with updated SDK usage and distributed tracing guidance for Node.js v4

Author: ggailey777

articles/azure-functions/functions-reference-node.md

@@ -1118,7 +1118,14 @@ Azure Functions lets you define the threshold level to be used when tracking and
 
 ## Track custom data
 
-By default, Azure Functions writes output as traces to Application Insights. For more control, you can instead use the [Application Insights Node.js SDK](https://github.com/microsoft/applicationinsights-node.js) to send custom data to your Application Insights instance.
+By default, Azure Functions writes output as traces to Application Insights. For more control, you can instead use the [Application Insights Node.js SDK](https://github.com/microsoft/applicationinsights-node.js) to send custom logs, metrics, and dependencies to your Application Insights instance.
+
+> [!NOTE]
+> Some methods in the Application Insights Node.js SDK have changed over time and might have minor syntax differences from the examples shown here. For the latest API usage, see the [Application Insights Node.js SDK documentation](https://github.com/microsoft/applicationinsights-node.js).
+
+::: zone pivot="nodejs-model-v4"  
+For distributed tracing in the Node.js v4 programming model, use the [`@azure/functions-opentelemetry-instrumentation`](https://www.npmjs.com/package/@azure/functions-opentelemetry-instrumentation) package instead of the Application Insights SDK. This package provides OpenTelemetry-based automatic instrumentation for Azure Functions. For more information, see the [OpenTelemetry Azure Functions Instrumentation for Node.js](https://github.com/Azure/azure-functions-nodejs-opentelemetry) GitHub repository.  
+::: zone-end
 
 # [JavaScript](#tab/javascript)