tuning box tells your edu to add more fuel and air, therefor creating more power, it can also tell the edu to put less fuel or air to create less power, i know that ecu remaping changes the way the ecu works, if the ecu only allowed for 2ml of fuel, the new ecu would allow 3ml of fuel which is pretty much telling the ecu that the engine needs more fuel and stuff, so in other words the both do the same thing, difference being one of them works along side the original ecu while the other one changes the original ecu, so the the mapper gets it wrong, you'll have engine problems lol
Stop trying to explain something you clearly know nothing about.
An ecu uses sensors, be them inductive, Hall effect, NTC, PTC etc. each sensor is provided with a voltage in order to work. This voltage is feed through the sensor and the varying state of said sensor alters the amount of voltage fed back to the ecu so it can accurately utilise this information and base the control over the engine on it.
What a tuning box does is manipulate the return voltage signal. The reading the ecu sees is false so it reacts how it is programmed within a limited manner. The ecu expects high fuel pressure but the box intervenes and tell the ecu the pressure is lower than expected so the ecu adds extra fuel. The ecu knows how much extra fuel but it has seen no increase in pressure so it adds more until it can add no more and reaches the height of its tolerance where it usually logs a 2nd priority fault code. The sane goes for the boost. The ecu sees lower than expected boost so it raises the pressure and the turbo has more demand put on it. It gets to a point where the ecu programming intervenes and stops any more boost, sometimes this will cause limp mode, as in a recent thread by someone else with a tuning box installed.
As I've already said - the tuning box DOES NOT WORK WITH THE ECU. It serves to trick it into working outside usual, in monitored parameters. So you tell us - what's safer? A piece of "dumb" unadaptive hardware that forces the ecu to work incorrectly or fully adaptive software that has a logic in control of what it can and can't do?
A tuning box uses resistive circuits, this is how the false signals are created.