Hey, good to know. Yeah, I think it makes sense to treat auto-hyphens and manual hyphens differently (or you could set it to take manual hyphens into account if the insertHyphens bool is turned off, because in that case it wouldn't matter).
It can be an issue for any situation where there isn't much whitespace around the RectTransform, because the hyphen ends up sticking out (especially with a monospaced font). And, as mentioned, it can be a problem when working with masks — this one is within a ScrollRect, and the Viewport has a mask. If the content and viewport are the same size, the hyphen ends up getting skipped entirely, because the whole char is outside the bounds of the viewport. I sort of worked around this by changing how the padding is set up, but you get the idea.