There’s a workaround in starting the PIGPGIO service in IPV4 only mode. That way you can disable IPV6 at system level.
/lib/systemd/system/pigpiod.service
ExecStart=/usr/bin/pigpiod -l -m -n 127.0.0.1 -p 8888
The -m option is not mandatory but for disabling the monitoring for the service, decreasing CPU usage by 7%