add multiple Musescore audio track to scores

As of now, it is possible to add mutiple audio tracks to scores, but only from videos from youtube. Some of my listeners would like to have an harpischord rendition of my pieces. I would like to avoid having to upload 2 times the same score, especially that I have hard time uploading them, usually 10/15 tries. It would be great if we could transfer several audio renditions directly inside Musescore at upload time.