I flew Islamabad - Karachi & back a couple of years ago.
On the outward trip, I flew Shaheen Airways. The plane was a Ukrainian registered wetleased Yak-42 (what fun). In good weather, the plane had a steeper angle of ascent than is common with BoeingBus. Once in cruise, the flight appeared to make continual slight alterations of heading.
The return trip was with PIA, which did not fly the direct route but much closer to the border with India, then altering course.
If not relevant, please feel free to ignore/delete this SLF observation.