Tragicomic! One would think that if they're adding in all of Latin-1, they'd go to the small extra trouble of adding in ways to represent the 3rd and 1st tones. It'd be 10 extra glyphs, but formed by making two glyph parts (ˇ and ¯) and adding it on to the pre-existing aeiou.

(One could even write Icelandic, since the fonts have þ and ð!)