I have no idea of who Kovid is and has done but Calibre is a great piece of software. It does exactly what I need: import files into a directory and occasionally let me edit them (text and metadata.) I sync with Synchthing. I'm really happy it got full text search over all the library. I'll use that too.

BTW, if we don't have to use software written by people we don't (or won't) like when we know everything they did or said, I bet we'd have to shutdown our phones and computers and never turn them on again.