Most input methods, including fcitx, don't follow the user-specified compose-key sequences in ~/.XCompose, but XIM specifically does. In the other direction, fc

Most input methods, including fcitx, don't follow the user-specified compose-key sequences in ~/.XCompose, but XIM specifically does. In the other direction, fcitx supports C-S-u NNN to enter characters by codepoint value but XIM doesn't. For the trifecta of compose-key, pinyin, and one-off symbols I haven't found anything better than switching off.