Generating silence at end of selection, then save

Mac 10.12.6
Audacity 2.1.3 [Using older version because current version adds menu layers to two things I do repeatedly. With a neurological disability, it is VERY difficult for me to slide a mouse left or right while staying totally horizontal. I have enough frustration using a computer, and V2.1.3 at least saves me two points of frustration per file when I process.]

When I select a middle section of a saved flac file, I want to generate 30 seconds of silence to the end of the selection, then save both the original selection plus the 30 seconds of silence into one file. When I select my range then >move curser to selection end>Generate>silence, then try to save, it only saves the 30 seconds of silence. I can see on the screen that my original selection is gone and only the 30 seconds is selected.

I have been saving twice, once the original selection, then open that file and add the 30 seconds and resave. But with a 40 minute symphony at hi resolution, it takes over 3 minutes to save the file, 30 seconds to open it again, then another 3 minutes to re-save.

Is there a way to streamline this process so I only have to save once?

—FYI (not necessary to read at all):
To answer the obvious question: Why do I do this? When I purchase or record off radio a music piece that is only one movement, it of course creates one file which I do not put into a directory. My players will play the next file without pause. The 30 seconds gives me the time to pick up the remote and stop the playing. The pieces I purchase with multiple movements (i.e., a symphony), with each movement being a separate file, my player will go to the next file but will stop at the end of the folder, so no need for 30 secs of silence.

Rather than making a selection, just click on the track where you want the silence. Then open “Generate menu > Silence” and enter the amount of silence that you want (30 seconds). This will insert the specified amount of silence at the cursor position.

For menu items that you use frequently, you can create keyboard shortcuts. See: Shortcuts Preferences - Audacity Manual

Perhaps it might be better to just split the track into separate files (like your bought recordings that have multiple movements).
See: Splitting a recording into separate tracks - Audacity Manual

Thank you, Steve. :sunglasses: