I am still able to use and edit in the editor despite passing the readOnly attribute and checking that it was passed into the component options.
<!-- Template code -->
<QuillEditor @name={{this.args.name}} @text={{this.args.text}} @delta={{this.args.delta}}
@onChange={{this.setChange}} @onEditorChange={{this.onEditorChange}} @modules={{this.modules}}
@placeholder={{this.args.placeholder}} @theme="snow" @readOnly={{true}}>
</QuillEditor>
Ember Inspector:

I am still able to use and edit in the editor despite passing the readOnly attribute and checking that it was passed into the component options.
Ember Inspector: