About the "Tx Baseband Waveform" section of AD9375 DPD GUI,
1. What is the DPD API setup command about the "Digital Scale x dBFS" ?
2. What is the DPD API setup command about the "Digital Freq Offset x MHz" ?
Digital scale and frequency offset are features provided in GUI for test purpose. This is not part of Mykonos and hence there are no API's for same.
You need to implement these in your baseband.