First of all, I want to make clear that I do not know what the real issue is. I want to use nerdfonts (https://github.com/ryanoasis/nerd-fonts) in vim through the devicons plugin (https://github.com/ryanoasis/vim-devicons). If you install the fonts and then try to print a character in konsole, for example: echo -e "\uf057" the characters appear too small. I am opening this bug report based on this github issue (https://github.com/ryanoasis/nerd-fonts/issues/127) that suggests that there is double-width character support missing from konsole. I do not know if this is the case or what it actually means. But I thought I could bring this to your attention in case it is a konsole issue.
Konsole supports wide characters and reserves two cells for them. This includes Unihan characters as well as characters from the Supplementary Multilingual Plane. U+F057 is a character in the Private Use Area. Konsole cannot know that it is an Han character. Whoever asked you to use that character should look it up in the official list of Unihan characters. http://www.fileformat.info/info/unicode/char/f057/index.htm