Folks, it is all open, driving pleasure because not much traffic and road is very smooth because it is new; compare to M3.
It is right, while reaching at FSD exit, you again have to get an entry card for M4. It is due to some financial settlements as confirmed by my source which will be resolved soon. It is nothing to worry about.
Just get out from FSD toll plaza after paying your dues/ticket, take a U-Turn, take a new ticket and get in at M4. Toll is PKR 90 from FSD to GOJ that is a bit high
Enjoy !!