The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. The word that U+04D9 forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
Schwa (Ә ә; italics: Ә ә) is a letter of the Cyrillic script, derived from the Latin letter schwa. It is currently used in Abkhaz, Bashkir, Dungan, Itelmen, Kalmyk, Kazakh, Kurdish, Uyghur and Tatar. It was also used in Azeri, Karakalpak, and Turkmen before those languages switched to the Latin alphabet. The Azeri and some other Latin-derived alphabets contain a letter of identical appearance (Ə/ə).