Advanced UWP MarkupExtension as IValueConverter + XAML Escape Characters

BooleanToTextConverter.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Markup;

namespace MarkupExtensionTest
{
    [MarkupExtensionReturnType(ReturnType = typeof(IValueConverter))]
    public class BooleanToTextConverter : MarkupExtension, IValueConverter
    {
        public string TrueText { get; set; }
        public string FalseText { get; set; }

        public BooleanToTextConverter()
        {
        }

        protected override object ProvideValue()
        {
            return this;
        }

        public object Convert(object value, Type targetType, object parameter, string language)
        {
            if (value is bool b && b)
            {
                return TrueText;
            }

            return FalseText;
        }

        public object ConvertBack(object value, Type targetType, object parameter, string language)
        {
            throw new NotImplementedException();
        }
    }
}

MainPage.xaml

<Page
    x:Class="MarkupExtensionTest.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MarkupExtensionTest"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <StackPanel>
        <ToggleSwitch x:Name="MyToggle">Toggle Me!</ToggleSwitch>
        <TextBlock Text="{Binding IsOn, Converter={local:BooleanToTextConverter TrueText='Is it True?', FalseText='Not True!'}, ElementName=MyToggle}"/>

        <TextBlock Text="{Binding IsOn, Converter={local:BooleanToTextConverter TrueText=Hello\&#x2C; I\&#x27;m True!, FalseText='Really Not True!'}, ElementName=MyToggle}"/>

        <TextBlock>
            <TextBlock.Text>
                <Binding Path="IsOn" ElementName="MyToggle" Mode="OneWay">
                    <Binding.Converter>
                        <local:BooleanToTextConverter TrueText="Hello, I'm True!" FalseText="Nope!"/>
                    </Binding.Converter>
                </Binding>
            </TextBlock.Text>
        </TextBlock>
    </StackPanel>
</Page>