When you aim down your sights, and try to look around with free look, the camera rotates much faster than it should.
This makes it very difficult to aim accurately using it.

The only workaround right now is "do not use it", which isn't exactly a good solution.
It feels like the aiming freelook is at least 2-3 times faster than standard, when it should, on the contrary, be more precise, or at least as much as standard aiming.