Use complex collision as simple

Hello, my question is how do I setup collision using complex collision as simple on a nanite enabled model? Right now I have duplicated the original model without nanite and am using the original mesh as a customized collision mesh. When working with LOD’s I could setup the collision to only be enabled when LOD0 is enabled, and with nanite there are no LOD’s. I want the custom collision mesh to only be enabled when close to the model and not be enabled at all times, as I am not sure how performance will be impacted. Thank you.