Thank you for sending the patch.
I think this will solve the problem if it is English multibyte characters.
However, I still find it problematic for use in Japanese and Chinese.
For Japanese and Chinese, we input alphabetic character strings called pinyin or romaji on the keyboard, and then convert them to kanji or hiragana by pressing the space key or other keys that have conversion functions.
Therefore, if the first character is fixed as shown in the video, it cannot be converted to Kanji or Hiragana.
For example, the character "ひ" can be created by typing "hi". Similarly, the character "い" can be created by simply typing "i".
However, if the first character is fixed and you type "hi" to create the character "hi," the character "hい" will be created.
https://www.apowersoft.jp/free-online-screen-recorder