Aw, while custom fonts and lettering is a good idea (Especially when updating the visual style for iOS 11), having a single property isn't sufficient.
There are 3 separate layout objects that control the sizing of the font depending on the width of the screen (ie, iPhone SE, iPhone 8 Plus, and iPad), so in order to properly add custom fonts, a mechanism to set the font for each layout object would be needed.
Aw, while custom fonts and lettering is a good idea (Especially when updating the visual style for iOS 11), having a single property isn't sufficient.
There are 3 separate layout objects that control the sizing of the font depending on the width of the screen (ie, iPhone SE, iPhone 8 Plus, and iPad), so in order to properly add custom fonts, a mechanism to set the font for each layout object would be needed.