Carefully managing your use of hard references will really help with your load times and keep your memory usage low.
Just because you CAN load everything at once, doesn’t mean you should and it’s going to ruin your player’s experience if they crash because they run out of memory.
In this video I go over the difference between hard and soft references in Unreal, how to transition to soft references and load your assets asynchronously as well as showing ways of communicating between blueprints without casting.
https://dev.epicgames.com/community/learning/tutorials/7eq6/unreal-engine-hard-vs-soft-references