The packet format is always the same. It's only a matter of interpreting it. If you want to use decoder addressing don't set the flag CV29_OUTPUT_ADDRESS_MODE when calling Dcc.init() and use the callback notifyDccAccTurnoutBoard() instead of notifyDccAccTurnoutOutput()
NB: If you have programmed your own central unit, you should use the same addressing scheme for the central unit as for the decoder. This would avoid confusion in the addresses. In my opinion Decoder addressing only makes sense if you also use corresponding decoders with 4 turnout outputs.