How to notify when a DataTemplate is loaded for the ContentPresenter (or ContentControl)

Question

I know similar question was asked and as a solution it was suggested to wrap the content in a DataTemplate with Grid and use Grid_Loaded approach. But if I have let's say 10s of DataTemplates that my template selector will select one at a time based on a condition then I need to add this Grid_Loaded event handler for each and every DataTemplate in the xaml. What I'm looking for another approach that wouldn't need me to do duplication of code.

<UserControl x:Class="WHATEVER">
    <UserControl.Resources>
        <ResourceDictionary>
            <my:DetailViewDataTemplateSelector x:Key="myDataTemplateSelector"/>

            <DataTemplate x:Key="Template1">
                <!-- some content -->
            </DataTemplate>

            <DataTemplate x:Key="Template2">
                <!-- some content -->
            </DataTemplate>

            <DataTemplate x:Key="BlankDataTemplate" />

        </ResourceDictionary>
    </UserControl.Resources>

    <ContentPresenter ContentTemplateSelector="{StaticResource myDataTemplateSelector}" Content="{Binding MyViewModelProperty}" />
</UserControl>

And my template selector is defined like (the passed in item is basically the value of MyViewModelProperty of the DataContext)

public class DetailViewDataTemplateSelector : DataTemplateSelector
{
    public override DataTemplate SelectTemplate(object item, DependencyObject container)
    {
        DataTemplate selectedTemplate = null;

        if (container is FrameworkElement element)
        {
            selectedTemplate = element.FindResource("BlankDataTemplate") as DataTemplate;

            if (item != null && item is SOME_TYPE selectedNode)
            {
                if (element != null && selectedNode != null)
                {
                    if (SOME_TYPE == SOME_VALUE)
                    {
                        selectedTemplate = element.FindResource("Template1") as DataTemplate;
                    }
                    else
                    {
                        selectedTemplate = element.FindResource("Template2") as DataTemplate;
                    }
                }
            }
        }
        
        return selectedTemplate;
    }
}

Just to let you know I tried using ContentControl instead of ContentPresenter and even created my own CustomContentControl inherited from ContentControl and overriding the OnContentTemplateChanged and OnTemplateChanged handlers, but none of those handlers are called when every time I change the value of MyViewModelProperty.

Note, that the template selector is called and the correct template is returned out based on the MyViewModelProperty value, but the abovementioned OnContentTemplateChanged and OnTemplateChanged handlers are not called after the template is selected. If I have a Grid as the first element in my DataTemplates and subscribe to Loaded event then that is called right after the DataTemplate, therefore, the Grid element is loaded.

Any ideas on how to avoid tying the Loaded handling to the internal grid and rather to fire somehow when we know that the ContentControl's template is selected by the selector and is loaded? Thanks a lot in advance.