IPA and some languages need glyphs that do not exist in precomposed forms in
Unicode. The only way to compose them is with combining diacritics.
For languages using those it's not a major issue since the alphabet is not too
large, we can use <charinsert>ɛ̀ ɛ́ ɛ̌ ɛ̂</charinsert> for example(that's U+025B
with diacritics U+0300, U+0301, U+0302 and U+030C).
For IPA, it would be necessary.
Currently adding a combining diacritic (any of U+0300-U+036B) between
<charinsert> tags does not work.
- <charinsert> ̀ <charinsert> is useless since the diacritcs is attached to the
preceding character, but we want to insert only the diacritics not the previous
character with the diacritic. Besides, it's not displayed at all.
- <charinsert>̂</charinsert> is not displayed either.
This isn't major bugs since any serious IPAer should have an input method
(there's close to none: one for Mac from SIL and uncomplete or buggy ones for
Linux). But it would be nice if it worked.