Crikey. Tell me you don't have a clue about a feature without telling me you don't have a clue about a feature.
Not sure what GS-mini has to do with this since in general it’ll have you flying faster than the minimum Vapp.
As long as it’s not routine I can’t see the problem with adding a couple of knots. My operator went down the “trust the load sheet” line, but it’s pretty obvious when the calculated approach speed is a little too low.
The aircraft (especially the A321) tends to wallow around and is very quick to decelerate further but reluctant to accelerate, even with a large thrust input. None of the Airbus series are happy about you entering the flare a few knots slow as I can vouch for from personal experience.