I have a scene that uses a lot of instancing to scatter out vegetation and props aso.

Now we need to render these onto cards used for projection and I'm wondering if there is any way in LOPS to cull not only geo but also instances based on camera distance.

It would be really cool if there was a way to export and render everything in separate layers. For example.
FG 0-10m, MG 10-30m, BG 30-100m aso.

I know I could technically fake this by setting up the camera clipping planes but I was wondering if there was a more procedural way of doing this, maybe similarly to how the auto select lod nodes chooses variants based on distance I was thinking maybe pruning based on camera distance is an option.

Has anyone done something similar in the past and could perhaps guide me in the right direction?

This thread discusses something similar, but using the camera frustum rather than Z-distance. You should be able to adapt it to do what you're describing.

https://www.sidefx.com/forum/topic/79055/ [www.sidefx.com]

The basic idea is to use a Wrangle LOP to run on PointInstancer prims, appending points to the PointInstancers' 'invisibleIDs' property. I have used a modified version of this approach in production and it does the trick well enough.