Surely 5 or 6 knots extra on Vapp (VLSconf3 opposed to Vref) won't have a significant effect on crab angle required.
Anyway here another FCOM reference
3.3.16 DESCENT PREPARATION
Check or modify the landing configuration. Always select the landing configuration on the PERF APP page : CONF FULL in the normal landing configuration. CONF 3 should be considered, depending on the available runway length and go-around performance, or if windshear/severe turbulence is considered possible during approach.