Notification text works on a completely different system than the menu driver, meaning that it has its own settings. You can find those in the menu Settings | Onscreen Display | Onscreen Notifications
. The catch is… that’ll let you change font and size, but not the aspect ratio, so you’ll have to find some font that’s stretched waaaaaaay out horizontally (800% width!) or… um…
Yeah, that’s about it. As a temporary workaround, I could probably hack together an ultra-wide version of one of my bitmap-style fonts (like https://fontstruct.com/fontstructions/show/1524214/e-keet-winterlate-bc for example) if that sounds appealing.
Sadly, I have no clue what it’d take to alter the notification display code to take aspect ratio into account, and that would be the real fix.