Create and delete text layer

Here's two options in one script. Main function will loop through all the items in the project to find compositions. If composition is found, it will execute function and will pass projectItem as an argument. Make sure to uncomment one you need.

Function addTextLayer(composition) will add a text layer that has custom comment "myTextLayer" and label = 0, so we can find this layer later.

Function removeTextLayer(composition) will loop through all the layers in composition to find a layer, that has comment "myTextLayer" and label = 0. Once it's found, it will remove it.

Enjoy.

(function () {
    try {
        app.beginUndoGroup("This is great");
        
        var projectItem;
        for (var i = 1, il = app.project.numItems; i <= il; i ++) {
            projectItem = app.project.item(i);
            if (projectItem instanceof CompItem) {
                // addTextLayer(projectItem);
                // removeTextLayer(projectItem);
            }
        }
        app.endUndoGroup();
    } catch (e) {
        alert(e.toString() + "\nScript File: " + File.decode(e.fileName).replace(/^.*[\|\/]/, '') +
            "\nFunction: " + arguments.callee.name +
            "\nError on Line: " + e.line.toString());
    }
    function addTextLayer(composition) {
        var textLayer = composition.layers.addText();
        textLayer.name = "COMPOSITION";
        textLayer.startTime = 0;
        textLayer.outPoint = composition.duration;
        textLayer.text.sourceText.expression = "thisComp.name";
        textLayer.transform.position.setValue([40, 82, 0]);
        textLayer.comment = "myTextLayer";
        textLayer.label = 0;
        textLayer.locked = true;
    }
    function removeTextLayer(composition) {
        var layer;
        for (var i = 1, il = composition.numLayers; i <= il; i ++) {
            layer = composition.layer(i);
            if (layer.comment === "myTextLayer" && layer.label === 0) {
                layer.locked = false;
                layer.remove();
            }
        }
    }
})();