Now, setNodeId does change TPDO and RPDO CobId without testing previous CobId in order to avoid confusion. Standard does not says when 'default value' should be applied. See DS301 - Object 1400h - 15FFh: Receive PDO Communication Parameter page 108.
<HTML>
<BODY>
<CENTER>
<IMG SRC="canfestival_overview.png">
<BR><BR><BR>
<IMG SRC="canfestival_CAN.png">
<BR><BR><BR>
<IMG SRC="canfestival_scheduling.png">
</CENTER>
</BODY>
</HTML>