The way FLEX (the assumed temperature method) is calculated allows full thrust at any moment. Maybe something got lost in the translation, but the answer from the performance provider as stated in post #1 makes no sense.
Somebody remind us, please, what happens in RTOW flex calculation once you hit the Vmu / minimum V2 limit from the FCOM. Do you just use the higher speed or are the FLEX calculation results disregarded altogether?