Bear in mind also, that even if you use TOGA, you well still be well under the rated thrust the engine is capable of.
In BA the same V2500 engines are fitted to A319/320/321 aircraft and it is just a pin change to upgrade the thrust you get with TOGA from 22K? on the A319 to 33K? on the A321. So an A319 at 22K TOGA is still massively derated in absolute terms.