nonlinearmind had asked about getting most volume possible.
SS_SWING of the SCI_STATUS allows you to go above the 0 dB volume setting. Value 0 is normal mode, 1 gives +0.5 dB, and 2 gives +1.0 dB. Settings from 3 to 7 cause the DAC modulator to be overdriven and should not be used. However, I doubt the receiving device will be able to handle it with out clipping.
At this time the released public GITHUB driver does not support a public member function to change this. Assuming 0dB should be loud enough.