Application Insights Telemetry Initializer to send the application version and a custom "tags" property

VersionTelemetryInitializer.cs

namespace Insights
{
    using System.Configuration;
    using System.Linq;
    using System.Reflection;
    using Microsoft.ApplicationInsights.Channel;
    using Microsoft.ApplicationInsights.Extensibility;

    /// <summary>
    /// Version TelemetryInitializer
    /// </summary>
    public class VersionTelemetryInitializer : ITelemetryInitializer
    {
        private static string version = string.Empty;
        private static string tags = ConfigurationManager.AppSettings["InstrumentationTags"];

        /// <summary>
        /// Initializes properties of the specified 
        /// <see cref="T:Microsoft.ApplicationInsights.Channel.ITelemetry" /> object.
        /// </summary>
        /// <param name="telemetry">the telemetry channel</param>
        public void Initialize(ITelemetry telemetry)
        {
            // Application Version 
            telemetry.Context.Component.Version = VersionTelemetryInitializer.version;
            // Environment Tags 
            telemetry.Context.Properties["tags"] = VersionTelemetryInitializer.tags;
        }

        /// <summary>
        /// Adds the VersionTelemetryInitializer to Microsoft.ApplicationInsights
        /// </summary>
        public static void Configure(Assembly assembly)
        {
            VersionTelemetryInitializer.version = assembly.GetName().Version.ToString();

            if (ConfigurationManager.AppSettings.AllKeys.Contains("InstrumentationKey") && !string.IsNullOrEmpty(ConfigurationManager.AppSettings["InstrumentationKey"]))
            {
                Microsoft.ApplicationInsights.Extensibility.TelemetryConfiguration.Active.TelemetryInitializers
                    .Add(new VersionTelemetryInitializer());

                Microsoft.ApplicationInsights.Extensibility.TelemetryConfiguration.Active.InstrumentationKey =
                    ConfigurationManager.AppSettings["InstrumentationKey"];
            }
            else
            {
                TelemetryConfiguration.Active.DisableTelemetry = true;
            }
        }
    }
}

This code is at least 4 years old, but:

1. I would need to to see the code to understand what can be happening there. With the information you provided it doesn't make sense for me either.
2. Neither the tags variable or the ConfigurationManager.AppSettings["InstrumentationTags"] configuration have effect on the InstrumentationKey setting or configuration.

Hope it helps...