[travisjungroth]

The straight bars over vowels are called “macrons” in English. https://en.m.wikipedia.org/wiki/Macron_(diacritic)

In Māori, there are ā, ē, ī, ō and ū.

[chevyray]

Ahh yes there it is, thanks for clarifying. These are quite simple and would be easy to support.

[bspammer]

Apologies if this nerd-snipes you, but supporting the caron might also be fairly simple given you could just vertically flip the circumflex https://en.wikipedia.org/wiki/Caron

Together with the macron, pinyin (the main romanization for Chinese) would be mostly supported. https://en.wikipedia.org/wiki/Pinyin

[chevyray]

Great suggestion, I would not have discovered this easily. thanks!