Using a series type in which the ShowInLegend property is default false, when we set this property to true and export and import it the property value is lost, e.g.

    System.IO.MemoryStream stream;

    private void button1_Click(object sender, EventArgs e)
    {
      tChart1.Clear();
      Steema.TeeChart.Styles.LinearGauge linearGauge = new Steema.TeeChart.Styles.LinearGauge(tChart1.Chart);
      linearGauge.Title = "titulo";
      linearGauge.Tag = "1\tx";
      linearGauge.ShowInLegend = true;
      linearGauge.RedLine.Visible = false;
      linearGauge.GreenLine.Visible = false;
      tChart1.Series.Add(linearGauge);

      tChart1.Series[0].FillSampleValues();
    }

    private void button2_Click(object sender, EventArgs e)
    {
      stream = new System.IO.MemoryStream();
      tChart1.Export.Template.Save(stream);
    }

    private void button3_Click(object sender, EventArgs e)
    {
      stream.Position = 0;
      tChart1.Import.Template.Load(stream);

     // tChart1[0].ShowInLegend = true;
    }