This has been spoken about before,and is a can of worms.i would,nt advise anyone to start adjusting engine parameters.as said there are insurance issues,added driveline strain,warranty problems etc.The tuning boxs are crude resister packs,the remap is generally a genetic recalibration that some tom, dick and harry,s come up with on his panasonic cf51 toughbook in his spare time.If things were that easy the manufactorers would do it.They spend millons on EDC systems,then a back street firm improves it?dont think so.
The figures they give are utter bull,what happens if the engine fails after a remap,will they stand by it?forget it.