I didn't find any practical way to set/change/save microphone gain level.
Ideally if there were something like
arecordthat was minimal and supported keybindings for raise/lower volume I suppose that might be an ideal solution - because right now the user is just dropped into st with arecord running. By default the mic is muted on the system and just unmuted during recording so I'm not positive on adding a global menu entry for mic volume changes.
Well I didn't think about menu ;) Rather right config file. Every time I start recording mic level is reset. And it seems to be different from levels of call. I'll check store/restore logic. But I'm still a bit confused in all those devices in alsa.conf.