To calibrate the ComfilePi's touchscreen, simply run the following command from the ComfilePi's desktop.
sudo /opt/ComfileTech/touch/rpi-AR1100/AR1100 -c 4
This will display a sequence of 4 crosshairs that need to be accurately touched to perform the calibration. After the calibration, the mouse device will be re-enumerated, so the touch-beep may no longer sound when the screen is touched. To remedy that, either reboot the ComfilePi, or restart the touch-beep service with the following command:
sudo systemctl restart touch-beep.service