I've had some luck by first stopping the autoscroll in the serial monitor and taking a general estimate of the gyro offset. Subtract that from the gyro readings then running a smoothing sketch on the results. Also, there's a bunch of calibration sketches out there for the MPU 6050. You might be able to substitute the LSM output. Take a peek at Joop Brokking's YT channel regarding drone gyro calibration.
J