Adding ltng:require component dynamically does not execute afterScriptsLoaded

I am trying to load a classic console related library only when the a Lightning Component is running in a VisualForce container. Unfortunately, adding the ltng:require component dynamically does not make the library available nor is the afterScriptLoaded method executed. Should this work?

Here is the helper function I am calling:

loadClassicLibrary : function(component) {
    $A.createComponent(
        "ltng:require",
        {
            "scripts": '/support/console/46.0/integration.js',
            "afterScriptsLoaded": component.getReference("c.classicConsoleInit")
        },
        function(scriptComp, status, errorMessage){
            //Add the new button to the body array
            if (status === "SUCCESS") {
                var body = component.get("v.body");
                body.push(scriptComp);
                component.set("v.body", body);
                console.log("'navigation: Helper: loadClassicLibrary: component added.", JSON.stringify(scriptComp));

            }
            else if (status === "INCOMPLETE") {
                console.log("'navigation: Helper: loadClassicLibrary: No response from server or client is offline.")
                // Show offline error
            }
            else if (status === "ERROR") {
                console.log("navigation: Helper: loadClassicLibrary: Error: " + errorMessage);
                // Show error message
            }
        }            
    );
},

Per the browser console, the script file is accessed at the expected time. What am I missing?