Workaround: manually increase the font of the controls

protected override void OnShown(EventArgs e)
{
    base.OnShown(e);

    var dpi = NativeMethods.GetSystemDpi();

    this.Font = new Font(this.Font.Name, this.Font.Size * dpi.X / 96, this.Font.Style);
    this.radMenu1.Font = new Font(this.radMenu1.Font.Name, this.radMenu1.Font.Size * dpi.X / 96, this.radMenu1.Font.Style);
    this.radCommandBar1.Font = new Font(this.radCommandBar1.Font.Name, this.radCommandBar1.Font.Size * dpi.X / 96, this.radCommandBar1.Font.Style);
}