Overwriting a narrow character with an East Asian wide character:

xxx ESC [ D 中:
xxx中

xxx ESC [ 3 D 中:
xxx中

Overwriting a narrow character with an East Asian wide character, in the middle
of an 80-column line with mixed narrow and wide chars:

xxx[...]xxx中文xxx[...]xxx你好xESC [ 25 G 版:
xxxxxxxxxxxxxxxxxxxx中文xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx你好x版

xxx[...]xxx中文y。xxx[...]xxx你好ESC [ 25 G 版:
xxxxxxxxxxxxxxxxxxxx中文y。xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx你好版