no idea, but the barcode can easily be coded to show fast track for you but not your guests, but group 2 for all of you

and... you cannot copy the barcode because once you use it once , anyone else that tries to use it will get rejected as you will be flagged as airside

i would not be tempted to try and doctor airport barcodes

while i said its programmed on the barcode, it might not be directly coded, the barcode will have the PNR somewhere and it may be that is used as some look up to see class of travel. ff status and determine fast track that way