Replying to Thruster mounting question

well i bought a new pair of thrusters and took them to my local shop to be mounted i told the guy i wanted them mounted center and he said okay then progressive because on the ski there is to places a classic and a progressive i said sure i want them center mounted thats all i know get them home today and there mounted at progressive but im almost positive its not center what do you think is it a big deal that there a cupple cm back because i ski mostly all park and rode center mount before i know these skis arent symetrical so if anyone has anything to say thanks