Wouldn't it work if you stream the resulting video as a Youtube Live stream? You would have to set a stream up in the Youtube creator web page, in order to get

Wouldn't it work if you stream the resulting video as a Youtube Live stream? You would have to set a stream up in the Youtube creator web page, in order to get a streaming key and with it, a full RTMP URL. Then in FFmpeg, use "-f rtmp://...your target url" as output. Youtube will stream a live video (which you can hide as "unlisted") and afterwards, the video will remain in the channel as a VOD.