Hey there, I have an alternate Common Lisp implementation of a QOA encoder and decoder that you may or may not want to list :) It's part of my larger CL-RemiAudio library, and is available here: https://chiselapp.com/user/MistressRemilia/repository/cl-remiaudio/
I'm already using this implementation in my music player Benben to provide support for playing QOA files. It also supports an extended form of QOA called Extended QOA Format (XQAF) that supports things like metadata to make it more of a general purpose format. I wrote a companion command line tool as well that can encode/decode both QOA and XQAF files called XQATool.