Feedrate in Trajectory sequence

When using a trajectory milling sequence and the arc feed control parameter is set to tool perimeter the feedrate of the tool will be reduced or increased depending on the size of theradius being cut if the trajectory is definedusing an edge. However if it is definedusing a datum curve the feedrate does not change. Is this a bug or intended functionality? Is there a workaround?

Does the cldataoutput for the toolpath reflect GOTO / points or CIRCLE /? If you only see GOTO and not CIRCLEstatements, then you will not get any slow down feedrates as there are no arcs to adjust the feedrates with.