Extract from QRH Overweight Landing (CFM eng)
LDG CONF...........AS REQD
Use the ECAM flap setting if required for abnormal operations. In all other cases:
-FULL is preferred for optimised landing performance.
-If the aircraft weight is above the maximum weight for go-around (given in the table below) use FLAP 3 for landing.
In all cases, if landing configuration is different from FLAP FULL use 1+F for go-around.
As I cannot reproduce the given table a summary of the CFM numbers shows that an overweight climb gradient can be achieved at Max Ldg Wt 77T in FLAP 3 at OAT +40C and Airport Elev 3000ft, +30C/6000ft to +15/8000 which would probably not be often if you are operating outside of those numbers.
Obviously if you or your Company choose to land FLAP 3 as a matter of course then the situation is changed.
