If you go into the Alpha Codes in the AIDS and insert GWFK (or GWFP if you work in lbs), the FAC computed gross weight will be displayed. This is what your GD, VLS, Alpha Prot and Alpha Max is computed from when airborne. If your FMGC weight is different, just add or subtract one knot per tonne difference for the FMGC compted VAPP and you will have the 5 knots above VLS.
Vary rarely are loadsheets accurate when using notional weights. People are getting heavier and their handbagge often weighs above the allowed maximum- the aircaft is nearly always heavier than the loadsheet says.