If you are using queues of any kind you need to inspect a packet, classify it , and place it in a queue, so that you know when speed limit is reached , queue is full and you an start dropping the packets (limiting speed).
Fasttrack is all about skipping those processes, that is where that speed comes form.
It is like "face control" in the nightclub
Fasttrack is friends and celebrities that are known to guard that get in as soon as face is recognized.
Queues are regular people in the line that you stand in to get in the club, and in the end they will check your ID, bag and pocket content, and might be discarted
You can't have both, you can't have celebrity approach with deep pocket and bag inspection at the same time, can you?