I downloaded Primo Levi's The Periodic Table (Excellent series ) and found the volume too quiet for my bluetooth player, even at maximum volume on my player and the amp. I found the same with the MP3 direct download.
FFMPEG to the rescue.

for %x in (*.mp3) do ffmpeg -i %x -vcodec copy -af "volume=10dB" 10db_%x.mp3

(You can also use a multiplier instead of decibels)

and the result was much louder, without being distorted.

Question. Can I do this on a per show basis at record time?

See custom commands section of examples page in wiki