neither worked for me, tried both but was still for some reason or another writing the log file to nextcloud share not within the appdata. so i combined both ideas and it worked!
in the config file i added:
'logfile' => '/var/log/nextcloud.log',
'logfile_audit' => '/var/log/audit.log',
then in the nextcloud's own console i did touch and chown abc for both files
so i ran:
sudo touch /var/log/nextcloud.log
sudo chown abc /var/log/nextcloud.log
sudo touch /var/log/audit.log
sudo chown abc /var/log/audit.log
restarted the container and voila! its now logging to within the appdata, no more disk spin ups!