This character is a Other Letter and is mainly used in the Lisu script.
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+A4F0 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:
The Fraser or Old Lisu script is an artificial abugida invented around 1915 by Sara Ba Thaw, a Karen preacher from Myanmar and improved by the missionary James O. Fraser, to write the Lisu language. It is a single-case (unicameral) alphabet. It was also used for the Naxi language, e.g. the 1932 Naxi Gospel of Mark and used in the Zaiwa or Atsi language e.g. the 1938 Atsi Gospel of Mark.
The script uses uppercase letters from the Latin script (Except for the letter Q) and rotated versions thereof (Except for the letters M, Q and W), to write consonants and vowels. Tones and nasalization are written with Roman punctuation marks, identical to those found on a typewriter. Like the Indic abugidas, the vowel [a] is not written. However, unlike those scripts, the other vowels are written with full letters.
The local Chinese government in Nujiang de facto recognized the script in 1992 as the official script for writing in Lisu, although other Lisu autonomous territories continue to use the New Lisu.