CSS injector doesnt like symlinks

I tried to symlink to the css_injector_X.css-file from a css-file I have in a better place on my server but css_injector wasnt able to read the file, it is the first time I have experienced something like this.

The reason why I had to do this is because of the lack of folder-support and lack of possibility to give a path instead of copy-pasting the content of the file into a new css_injection-rule.
#335574: Place css_injector_X.css in folders
#335571: Abillity to link to existing css-file instead of making a new