According to _Understanding Japanese Information Processing_, the
character set most widely used in Taiwan is called Big Five, which
specifies 13,000 characters. However:
The authors of _An Introduction to Chinese, Japanese, and Korean
Computing_ claim that the designers of the Big Five code actually
copied many kanji from the JIS standard. Many kanji exist in both
Chinese and Japanese, but there are some subtle glyph differences
between them. The Big Five contains many non-Chinese versions of
kanji (and not the actual Chinese equivalent), and no attempt was
made to remedy this problem.
It sounds to me as if a lot of Big Five will get absorbed through
unification.