Yeah, it is written in the logs, but not too frequently (like at startup) so you’d end up having to ensure the python script was started before PathPilot (example, using systemd to start it).
Honestly, if it were me, I’d just define it in the config section, and make it slightly different per machine in my shop I was running this on. Set a machine constant, or customize the topic strings for each machine, eg:
change: MQTT_TOPIC_INTERP = 'pathpilot/interp_state'
to: MQTT_TOPIC_INTERP = '770M/pathpilot/interp_state'
and repeat for the topics you are publishing.