Hey, i’m not sure if you understand what i’m asking but i use the same logic use by this vidéo : https://youtu.be/4ddbnQIuwAM?si=3g90Due-dY6e_bFM, like my system is the same as is first video, just a got more room and more actor, and my room list is set to 1000000 because i need this number of room for my project, and i was wondering is their a way to add something that can Unload and load part of the level because 1000000 room with hundred of actor each can easly crash a computer. Thanks in advance for reading and your time, if you need anything ask me 
(i give you all my content in my BP_LevelGenerator and how is made my BP_MAster Room and a Exemple of another Room Name Child Room if you need more ask me but i meanly follow the youtube video i put in the post
First of all. I would avoid making the whole level in an Actor BP. That’s not how an Actor BP should be used. The way you are using it is technically wrong and will cost you performance.
A better approach is to use level streaming. Since this is not an “open world” kind of direction, the best bet you can get is to utilize level streaming feature. Instead of calling it inside an actor BP, you can use a level BP instead. It gives you much more control and freedom and will solve rendering-twice issues or HLOD, if any.
i see i see, first, thanks for the answer. Should i rewrite the code in a Level BP entirely ? i not sure if the result will be the same, i never use a level BP before and i don’t know if the code will still work or if i will need to change things. do you have any clue by chance if this will “Theroicaly” Work ?
The right question to ask is whether you know how level streaming works or not. If you do, then level BP will not be a problem.