Not sure if it’s too late to help you with the sky, but in your post process material, you can implement a mask for your skybox using a distance that’s set high enough that it won’t interact with your environment, but will still mask out your sky (might have to scale the skybox larger depending on how it’s set up).
Use a scene depth, plug that into an ‘if’ variable, and check it against the distance you want it to transition at. Then you can use this mask to plug into different parts of your post process material and pull back effects such as the detail on the sky box while maintaining the look for the rest of your game.
Hope that helps!