I have enabled the serial.log to check for any oddity going on, and I've noticed there is some rotation mechanism, but not via the system logrotate that I can find. How is this being done and is it user configurable?
I believe it rotates every time the connection to the printer is reset. It's all done using Python's built in logging module.
There is some flexibility with logging. See logging.yaml.
I did see that but nothing specific on when it rotates and how many it keeps.