May you confirm that it depends from operator or by the airplane manufacturer
In all my recent operators, using full vertical & lateral navigation guidance, the full landing configuration was an operator's SOP. It was either an AT point or a No Later Than. To expand on that; the AT point was identified to be the point of Gear Down Intermediate Flap so that the final configuration was achieved by a No Later Than point. These days, with Landing Gate and stabilised criteria the latter is taken care of with belt & braces.