Hello Burmo,

A possible approach to achieve this might be by using CreationFilter, please look at my code:

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            ultraExplorerBar1.CreationFilter = new CF();
        }
    }

    class CF : IUIElementCreationFilter
    {
        void IUIElementCreationFilter.AfterCreateChildElements(UIElement parent)
        {
            if ( parent is EditorWithTextUIElement && parent.Parent is UltraExplorerBarGroupHeaderUIElement)
            {
                parent.Rect = new Rectangle(0, 0, 0, 0);
            }
        }

        bool IUIElementCreationFilter.BeforeCreateChildElements(UIElement parent)
        {
            return false;
        }
    }

Please feel free to let me know if I misunderstood you or if you have any other questions.