Hi, thank you for audacity! It’s great and I use it already for some years.
I often have to do the same steps and I would be glad to do it with a chain:
(for I use the german version maybe I don’t use the right labelling)
1.) split Stereo into two Mono tracks
2.) delete the second track
3.) increase the whole track
4.) copy the whole track
5.) create a new track
6.) paste the track into the new track
7.) create a Stereo track
8.) Export
regards!
Theo