Let me try and explain this as simply as I can. The philosophy behind GSmini has nothing to do with transient gusts. It's about maintaining an acceptable kinetic energy level (ground speed) and potential energy level (remaining thrust available) AT TOUCHDOWN.
Picture this. You're at 1000ft and you have a headwind of 65kts. Tower reported wind is just 20kts headwind. The 65kt headwind stays until you're 250ft AGL. Then in a span of a few seconds, you suddenly lose 45kts headwind and consequently your IAS too.
Now you're uncomfortably close to your stalling speed, and the engines are almost at max thrust trying to make up for the lost airspeed. You don't have the airspeed to land safely, nor do you have the thrust to carry out a safe go-around so close to the ground.
GSmini mitigates this by adding extra speed when it anticipates such a condition by measuring the difference between current wind during the approach and wind entered in the MCDU
PS If you think I'm making up such wind conditions, I'm not. It's just a regular day at UGTB or OBBI
