I am using the MarkerStyles to control display of points.  Setting it to a style seems to always "take" but setting it to null does NOT always take (sometimes it has to be set 10+ times!)
Code:pointSeries.MarkerStyles [ i ] = null;
// a small percent do not "take" for reasons unknown. So we just try real hard and they go through.
int cnt = 0;
while ( pointSeries.MarkerStyles [ i ] != null )
{
  // does not seem to help any
  //System.Threading.Thread.Sleep ( 1 );
  Console.Write ( "." );
  pointSeries.MarkerStyles [ i ] = null;
  cnt++;
  if ( cnt > 100 )
   System.Diagnostics.Debugger.Break ( );
}


Full code at https://github.com/bl0rq/NevronPoC/tree/master/NevronPoC

Thanks!