Help with unloading asset's after instances have been destroyed to reduce draw count

I have this one section in my game that’s like hugeeelyyy unoptimized but it’s not too much of an issue on it’s own but once other sections load into the game on top of it, that’s when it becomes an issue. This section im talking about has 5000 draws im not kidding either. I just need to know a way to deload this area after it’s been destroyed and erase all draws from the memory. Is that even possible? do they automatically ‘unload’ after the game detects no more instances with the asset id’s are in game? Any help appreciated

ps: i will remake the insanely unoptimized area post-release. the optimization of the build isn’t the issue i’m trying to resolve so don’t concern yourself with that