Is it possible to keep every level set on 'Always loaded' in a open world game without make all of this too heavy to load?

Hi, my question is: is it possible to keep every level set on ‘Always loaded’ in a open world game without make all of this too heavy to load?
This because every sublevel I create is always set on Blueprints by default, but when I click Play button my game do not show me the objects contained in the sublevels. So I set them on ‘Alweay loaded’. Is it right or wrong? Because i do not understand if I keep each sublevel loaded it will require a huge stuggle to load them.

Thank you ThompsonN13 to answered me! Anyway, what I mean is that I do not understand if keeping loaded every sublevel in game (with “Always loaded” option) it requires a great struggle for cpu and gpu. A

nother thing, I do not use level streaming or world composition.

what would be the point of having separate levels is they are all always loaded?

are you using level streaming or world composition? if its world composition i would think that the always loaded option would be meant for a major landmark that could be seen from far places ( im thinking death mtn in zelda oot). of course thats just speculation on my part since i havent used the setting you mentioned and havent researched it.

if a level is loaded then it will require more resources. if that will put a strain on your hardware well that depends on the levels and your hardware. if the levels are full of things such as moving objects and high poly models then that will sap performance. if your running the game on a top of the line pc you will have more performance to work with than if your running the game on a potato. so its not a simple answer. i guess the best thing to do would be to set it up and then do some profiling of the performance of the game to see how the extra levels affect the experience. level streaming at least from my experience is a tool to help performance by unloading things that you dont need, if things dont exist then they dont need to be rendered and dont require calculations or memory.

oh and you say you dont use level streaming but then in your picture you have change streaming method highlighted which is the method to stream your level ala level streaming.