So i found a definite reference by the FAA
https://www.faa.gov/other_visit/avia.../InFO11012.pdf
Purpose: This InFO informs air carriers and operators of the proper transponder selections during
aircraft taxi, in order to support air traffic control (ATC) ground surveillance systems as well as
minimize 1090 megahertz (MHZ) frequency congestion.
@coastrider26 so the FAA is not happy with your A330s
Discussion: TCAS II operation on the airport surface provides no safety benefit, except when
approaching or taxiing onto an active runway. Routine ground operations with the transponder selected
to TA-ONLY or TA/RA enables TCAS II to interrogate other aircraft at high power levels. This
unnecessarily contributes to 1090 MHZ frequency congestion. Routine operation of TCAS II on the
ground can degrade:
Performance of ATC radars
Surveillance performed by airborne TCAS II units in the vicinity of your aircraft
in the plates for EDDF you can find:
To ensure that performance of systems based on SSR frequencies (including airborne
TCAS units and SSR radars) is not compromised, TCAS shall not be activated
before approaching holding point. After landing, it shall be deselected after
vacating RWY.