Hmmm. No replies!
Btw, I am back with an awesome trip. I made it to the Rock Formations, Princess of Hope, 81 km short of Ormara.
I found the last CNG station at Hub. There are two actually; one is about 4 km from the Hub Checkpost, RCD CNG right after the PSO pump, and the other is further 1 km ahead, operated by Attock Petroleum. I was told by the fuel guy that there are no CNG stations afterwards and he was right. I switched to Petrol and refilled from the PSO pump in Winder, ~50 km ahead of Hub.
It took me less than two CNG refills and less than half petrol tank to cover a distance of 621 km, however, mostly without AC.