I have created a custom style for Labels in my application, this works fine and I apply a Template to achieve the other set styles that I need, again this works fine.

STYLE DEFINITIONS:

<Style TargetType="{x:Type Label}">

  <Setter Property="Background" Value="{DynamicResource BackgroundBrush}" />
  <Setter Property="Cursor" Value="Arrow" />
  <Setter Property="FontSize" Value="{DynamicResource Font_Regular}" />
  <Setter Property="FontWeight" Value="{DynamicResource 400}" />
  <Setter Property="Foreground" Value="{DynamicResource ForegroundBrush}" />
  <Setter Property="HorizontalAlignment" Value="Left" />
  <Setter Property="Template" Value="{DynamicResource Label.Default}" />
  <Setter Property="VerticalAlignment" Value="Center" />
  <Setter Property="VerticalContentAlignment" Value="Center" />

</Style>

<ControlTemplate x:Key="Label.Default" TargetType="{x:Type Label}">
  
  <TextBlock Style="{DynamicResource Label.TextBlock}"
             HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
             Text="{TemplateBinding Content}"
             VerticalAlignment="{TemplateBinding VerticalAlignment}" />

</ControlTemplate>

<ControlTemplate x:Key="Label.ItemHeading.Emphasis.Highlight" TargetType="{x:Type Label}">

    <TextBlock x:Name="lblContent"
               FontWeight="{DynamicResource 500}"
               Foreground="{DynamicResource HighlightBrush}"
               HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
               Style="{DynamicResource Label.TextBlock}"
               Text="{TemplateBinding Content}" />

</ControlTemplate>

- - -

<Style x:Key="Label.TextBlock" TargetType="{x:Type TextBlock}">

  <Setter Property="Background" Value="Transparent" />
  <Setter Property="FontFamily" Value="{DynamicResource Inter}" />
  <Setter Property="FontSize" Value="{DynamicResource Font_Regular}" />
  <Setter Property="FontWeight" Value="{DynamicResource 400}" />
  <Setter Property="Foreground" Value="{DynamicResource ForegroundBrush}" />
  <Setter Property="Padding" Value="5" />
  <Setter Property="TextWrapping" Value="Wrap" />
  <Setter Property="VerticalAlignment" Value="Center" />

</Style>

USAGE:
<Label Content="{Binding Reseller}"
       ContentStringFormat="Powered by {0}"
       Grid.Column="1"
       HorizontalAlignment="Center"
       Template="{DynamicResource Label.ItemHeading.Emphasis.Highlight}"
       VerticalAlignment="Center"
       x:Name="lblPoweredBy" />

I have now hit one short coming of this control and it relates to my Label having a ContentStringFormat value:

EXPECTED:
Label (lblPoweredBy) should output “Powered by MyCompany”, but instead it just outputs “MyCompany”

I tried adding StringFormat {TemplateBinding ContentStringFormat} to the Text property of the TextBlock, but at runtime it says this is incompatible. Can anyone help out?