Large Skyboxes and Hint/Skip

I’ve heard it’s a bad idea to make a huge skybox at the top as it will mess with visleaves and hint/skip… okay. I see. But then how do I, say, have a city map, with air vehicles constantly flying above, yet still have hint/skip and proper visleaves?? r_lockpvs tells me somethings such as: how i can see so much that is shouldnt see, even with hint/skip… so what’s the solution???

But those air vehicles are supposed to be just a decoration or for players to drive? If the first one, then there is no problem, they can just fly through hints, walls, whatever. Or better just fly in 3d skybox, outside actual level.

to help with reducing render distance use a Env_fog_controller if you want a large flying space
By adding fog to a level, you can hide a FarZ Clip Plane, and reduce the amount of rendered geometry, improving game performance. https://developer.valvesoftware.com/wiki/Env_fog_controller

They’re for players to drive.