PAC3220 ModbusTCP data for THD-V in 3P3W mode

Hello,

We are communicating to a PAC3220 with ModbusTCP and have found that we can read the THD-V (Y) when the device is in 3P4W mode, but we cannot read the THD-V(delta) in 3P3W mode as it is not in the Modbus map, and the THD-V (Y) becomes "-nan". 

From the manual (see attachment) the THD-V L1..L3 is only available in 3P4W mode, but THD-V L1-L2, L2-L3, and L3-L1 is available in 3P3W mode.  

Has anyone been able to read the phase to phase THD-V over modbus?  It is reading on the meter.

Thanks in advance,

David.