After the TALPA review, FAA advisory, EASA mandated, the revised operational landing performance (opposed to ‘actual’ distance) is much closer to the factored performance required for dispatch.
Thus a pre landing assessment based on the most recent performance standard (OLD), plus 15% Minimum (FOLD), should minimise any difference between pre-deprture landing performance and that required by a inflight assessment.
What is the basis of your in flight data (all of Airbus is OLD / FOLD)