Two other things I did not address.
#1 - Steve… in my method you can see that I went with what I originally thought the person was trying to explain in his stereo to 5.1 thread, and not what you said he may have been explaining (although I know you were not certain either https://forum.audacityteam.org/t/convert-audio-to-5-1-as-in-this-other-thread/16580/1). This is not because I think my explanation was right but only because I couldn’t hear enough of a difference between the two methods to warrant the extra steps. Your explanation may in fact be more precise.
#2 Quick Keys
I tried out Quickeys and I tried to tighten the script to do this. It was kind of frustrating because I had to put a lot of pauses in. It would work sometimes, but not others. So, in the end, I just put a 0.5s pause in between most commands and told myself that I will just have to wait 2 minutes to get a song done. This isn’t bad for me, because I only do a few a week. If needed, I may tighten it up.
So, Quickeys seems to be working consistently now, but I will keep trying it for the trial period. There are a few different ways to do things in this program and I doubt I am using the most efficient. I am pretty certain I will purchase it even if just to accomplish this.