What is best and optimized Technique of level Handling in Parking game ? loading from resources or enable in hierarchy

I am developing a parking game in which i have 50 levels. The outer environment including buildings and floor is similar in all levels. I have created levels prefabs with different props like cones, cars, boxes and arrows. i am instantiating these prefabs from resources . I am searching for which is best approach to handle levels i.e. 1) all levels present in hierarchy and are disabled and only current level prefab is enabled in start or 2) i have to instantiate each level from resources when level is selected. I am working only in one scene.

  1. If you are solo developer, and you don’t get runtime memory issues with your assets and loading time is good enough for you then this is viable option for you.