A box can never be as good as real software. The box only tricks the computer into producing a higher injection pressure.
On the one hand, it can be harmful with too high a set pressure, and on the other hand, the car’s other auxiliary systems will not work as well as correct programming of the control unit.
For example, the anti-slip system uses the information from the engine controller to know which torque the engine is developing.
With a box fitted, the information will not be correct, which can impair the function of the anti-slip system, even the electronic differential brake will not work as intended by the factory.
In addition, the trip computer will show incorrect fuel consumption figures, etc…