Rather you than me.....
All that does by the look of it is plug in to the injector loom and fool the engine in to injecting more fuel than it should be...... No increase to boost, no adjusting the boost control, safety paramaters to suit.....
The reason it gives great MPG by the way is because the trip computer has no idea you are getting the extra fuel, so it thinks you are using less than you actually are.
Get a proper remap for the same money