Private pilot here, so no experience of the A320.
However, I can read in the A320 FCOM (version from 17-OCT-2017):
AIRCRAFT TRIMMING
Ident.: DSC-27-20-10-70-00002179.0001001 / 09 DEC 09
Applicable to: ALL
When the aircraft is :
‐ In normal cruise range (around M .77),
‐ In straight flight,
‐ With the autopilot engaged,
‐ With symmetrical engine thrust, and
‐ With fuel in the wing tanks distributed symmetrically,
the rudder trim should stay between 1 ° right and 2.3 ° left.
Note:
This indication corresponds to a true rudder deflection within ± 1.5 °, taking into account the
permanent offset of rudder trim indication, when the aircraft is in cruise conditions. (average
0.5 ° right, 0.8 ° left).
An indicated, rudder trim above 1 ° right or 2.3 ° left is acceptable, if maintenance personnel
establishes that the corresponding real rudder position is within 1.5 ° left, and 1.5 ° right.
These values 1 ° right or 2.3 ° left are quoted in other places of the FCTM, so maybe they are also considered as the standard valid range for take-off configuration check.