Before I start looking at compiling oggenc https://github.com/xiph/vorbis-tools/bl ... c/oggenc.c ... is that necessary or have I overlooked perhaps it already being available in Fatdog? Can't find it in gslapt or the standard build.
Cheating and slapped wrist (but in a container so no harm/risk) I downloaded this bin https://github.com/Kode/oggenc_bin and dropped it into /usr/bin and its working well. Much better compression than flac.
Gist of what I do ...
set alsa to appropriate/reasonable levels ...
amixer -c 1 set 'Mic Boost' 80%
amixer -c 1 set 'Mic' 80%
amixer -c 1 set 'Capture' 80%
amixer -c 1 set 'Headphone' 80%
amixer -c 1 set 'Master' 80%
amixer -c 1 set 'Mic' unmute
amixer -c 1 set 'Headphone' unmute
amixer -c 1 set 'Master' unmute
Set off a laptop web cam image snapshot every 5 seconds and store that in /tmp/webcam.jpg
ffmpeg -hide_banner -loglevel error -y -f v4l2 -video_size 1280x720 -i /dev/video0 \
-r 0.2 -qscale:v 2 -update 1 /tmp/webcam.jpg
that's copied to a remote system
Have the laptop mic recording all of the time and forwarding that over ssh to a remote system
arecord -c 1 -f S16_LE -r 22050 -D plughw:1 | oggenc - | ssh userid@77.76.75.74 'cat - >/var/www/htdocs/obsd/sound.wav'
... where I'm now using oggenc instead of flac and that's lowered bandwidth through ssh considerably, around 5x less 
I drop the image and sound into a web page/httpd server so they're accessible from anywhere and for me its a granny (90 year old mum) monitor.
Tether the image/sound server laptop to a android phone for <15GB (with oggenc) monthly data bandwidth and some sims charge less than £5/month for that (could be run even without fibre/cable internet, just power, where mains power to the laptop can also charge the usb connected android phone).
Next planned phase is to use scrcpy along with vnc server on the voice/image server laptop for additional functionality/options. Sound is a laggy, 3 to 8 seconds delayed type lag via arecord | oggenc | ssh , so conversing via ssh isn't as nice as being able to call the laptop attached android phone and use vnc/scrcpy to remotely also answer that call and flip it to hands free with the volume whacked up to full, before having just android phone to android phone talk enabled whilst I'm on the way to assist her (by design we live pretty close to each other, which was a good move as she now has modest dementia).
All that aside, oggenc would seem like a good thing to have available either in the Fatdog base system or in gslapt.