Every application is different for sure, yes, as my boy bassjunkie said, i´ve lowered the peak frequency of the build by adding more power in the past, this has happened to me only a couple of times , i can give you this statement, adding more power lowers your peak frequency IF THERE´S A CHANGE, once again, this isn´t a constant, sometimes peak doesn´t move at all, i´ve never seen someone that has raised the peak because of adding more power, but you never know!!
If you are gonna meter the car, i would burp the same peak frequency you had before adding more power, and then, i would burp 2 frequencies below that, if score drops then you know the peak frequency it´s the old one or maybe only 1 hz below that, i wouldn´t waste my time burping above the usual peak