How do I use a custom font in my app without setting the font family for each element to the static resource?

Question

I have a Windows 8.1 Universal app for desktop that I am making and the client insists we use the Gotham font. We are using ttf version of the font and I have it in its own "Gotham" folder in the /Assets/Fonts/ folder. I need to "package" this font and use it in every part of the app such that it will work even when the client's device does not have the font installed on their system.

From my research, I can only find the option of setting the font family as a theme resource in the resource dictionary of the App.xaml page, then calling it for EACH page element that uses it.

FontFamily="ms-appx:///Assets/Fonts/Gotham/Gotham-...ttf#Gotham"

(Where the ... is "Bold" or "Light", etc.)

My supervisor really dislikes this method and wishes to be able to use FontWeight to get the weight and he wishes to just be able to set the font family in the app.xaml. Currently I set it like this:

<Application
    x:Class="UndisclosedAppNameHere.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:UndisclosedAppNameHere">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.ThemeDictionaries>
                <ResourceDictionary x:Key="Default">
                    <FontFamily x:Key="GothamFontFamily">
                        pack://application:,,,/Assets/Fonts/Gotham/Gotham.ttf#Gotham
                    </FontFamily>
                </ResourceDictionary>
            </ResourceDictionary.ThemeDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

What is the correct way to do this? Is setting the font family for each element the ONLY way to go or can it be done how I wish?

Thank you,
Zach