Tested with 4.5.1 and 4.6.0 and 4.6.1 Shipping build do not accept comand line arguments like “?Param1=Value1?Param2=Value2”. Is it a bug, or there is some trick to turn it on?

Did you custom the console command that is being used by you? First you should know that UE will not allow you run most console command when you shipping your project, unless you created it and parsed it self.