With the PhysX based lidar it is not possible to offset the vertical FOV.
We just introduced some a basic example with RTX lidar in 2022.1.1 today (Docs should be updated soon).
In 2022.2.0 later this year we will be doing a full replacement of the current lidar extension with RTX lidar and they should have feature parity. The RTX lidar sensor is much more configurable and should support this usecase.