With the new emonPiCM software “Native RFM69 (New)” that you chose, there is no need for the complicated and inflexible calibration = 110V, you can calibrate the voltage exactly in emonCMS using Setup →Admin → Serial Monitor, using that to send calibration commands to the emonPiCM in exactly the same way as you would with a programmer and laptop to an emonTx.
The documentation is part of the emonPiCM release: The emonPiCM