Alex
My interpretation, as an ex Airbus pilot and current Boeing pilot:
GS mini is an excellent feature in providing protection to wind variations on the approach. Most relevantly, imho, when you have microburst activity.
Consider the scenario where you have a tower wind component of 10kts Headwind:
Instantaneously on the approach you encounter 50kts HWC - GS mini will add up to 40 kts IAS (50-10) giving a constant GS approach (=constant power). It will also help protect you when (in a microburst) the 50 kt HW becomes a 50 kt TW.
The system is not perfect, but it sure helps in microbursts.