Legend behavior breaks when moving Legend outside of Chart control

I followed this post http://support.scichart.com/index.php?/Knowledgebase/Article/View/17244/39/tutorial—custom-legend-with-color-picker-and-custom-point-markers for creating a custom Chart Legend and it worked great. One feature of it that I really liked was the checkbox behavior: CheckedChangeZoomExtentsBehaviour.EnableZoomExtentsOnChecked=”True” which zooms the chart to extents everytime you show or hide a series.

This checkbox behavior breaks when I move the Legend outside of the chart, which I accomplished by following this post: https://www.scichart.com/questions/question/moving-legend-outside-sci-chart-plots

How can I keep this checkbox behavior when moving the Legend outside of the Chart area?

Note: if I set ShowLegend=”True” in my s:LegendModifie> tag, the behavior properly works with the legend outside the Chart area, but now I have duplicate legends both inside and outside my chart area with this setting set.

<!-- LEGEND_ITEM_TEMPLATE -->
<DataTemplate x:Key="LegendItemTemplate" DataType="s:SeriesInfo">
            <!-- DataContext is of type SeriesInfo -->
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>

                <!-- Visibility checkbox, bound to SeriesInfo.RenderableSeries.IsVisible -->
                <CheckBox Margin="5,0,0,0"
                    HorizontalAlignment="Left"
                    VerticalAlignment="Center"
                    behaviors:CheckedChangeZoomExtentsBehaviour.EnableZoomExtentsOnChecked="True"
                    Foreground="{StaticResource LegendTextBrush}"
                    IsChecked="{Binding RenderableSeries.IsVisible, Mode=TwoWay}"
                    Visibility="{Binding LegendData.ShowVisibilityCheckboxes, RelativeSource={RelativeSource AncestorType=s:SciChartLegend}, Converter={StaticResource BooleanToVisibilityConverter}}" />

                <s:PointMarker Grid.Column="1" Margin="5,0,0,0" Width="40" Height="10" VerticalAlignment="Center" HorizontalAlignment="Center"
                    DataContext="{Binding RenderableSeries}"
                    DeferredContent="{Binding LegendMarkerTemplate}"
                    Visibility="{Binding ShowSeriesMarkers, RelativeSource={RelativeSource AncestorType=s:SciChartLegend}, Converter={StaticResource BooleanToVisibilityConverter}}" />

                <!-- Series Name, bound to SeriesInfo.SeriesName -->
                <TextBlock Margin="5,0,5,0"
            Grid.Column="2"
            HorizontalAlignment="Left"
            Foreground="{StaticResource LegendTextBrush}"
            Text="{Binding SeriesName}" />
            </Grid>
        </DataTemplate>

<!-- LEGEND MODIFIER -->
    <s:LegendModifier x:Name="ChartLegend" ShowLegend="True" GetLegendDataFor="AllSeries" LegendItemTemplate="{StaticResource LegendItemTemplate}" ShowVisibilityCheckboxes="True"   />

<!-- MY LEGEND CONTROL ELSEWHERE ON THE PAGE -->
<s:SciChartLegend x:Name="legendControl" DockPanel.Dock="Top"
                                       Orientation="Horizontal" Margin="10"


                                       ScrollViewer.HorizontalScrollBarVisibility="Auto"
                                       ScrollViewer.VerticalScrollBarVisibility="Auto"
                                       LegendData="{Binding LegendData, ElementName=ChartLegend, Mode=OneWay}"
                                       ShowVisibilityCheckboxes="True" />