ARFoundation - Where to place directional? In scene or in prefab? To move during runtime

Hi guys

I need to be able to move my sun during runtime. Where is the recommended place to put the sun, taking into consideration my model is very large and in total covers 500meter.

For LWRP, I had issues getting the shadows to display consistantly, so I switched back to standard pipeline. I need to be able to change the sun position and rotation during runtime.

I also have a script that rotates the model in its own axis, and the sun should turn with it. Perhaps I should stick the sun in scene and turn the ARSession Origin instead?