Useless ZigZag indicator parameter

 
Hi all,

Trying to have a deeper understanding of the ZigZag indicator I was investigating its code. My finding was that the parameter ExtDeviation is useless so I checked it on the charts.
I attached two ZigZag indicators with ExtDeiavtion 0 and 1000. Independently of the timescale and zooming the two indicators _always_ covered each other. Even when I tried a higher ExtDepth for the two indicators (of course same ExtDepth for both) the results were the same.
Is it possible that the ExtDeviation parameter is useless? This would be pretty strange taking into acoount that ZigZag has been here for so long.
 

You may be right...didn't look at the code though