Any recommended methods working with a huge level?

I’m trying to create a huge map. I created it in World machine, split into 32x32 levels and added them using World Composition.
The resolution is pretty high. Every section is 1009x1009 so, it’s very difficult to do anything with it when all the levels are loaded.
When I try to apply, say, texture, I have to unload most of the levels, and then apply it to part of them, then unload, then load some more.
The same routine goes for applying height maps to textures, and also when I try to create level LODs, I have to do the same thing.
Otherwise, I end up crashing UE, giving me a low vram error.
I do have a rather beefy computer. I got a 1080 gpu(not Ti though), 6 core 12 thread 6800 cpu, and 32gb of ram, ssd for storage. Not top of the line by any means, but also not exactly low end.

Is there anyway to do it more efficiently? Is there any standard method when working with high res, large maps, or is this just the way it has to be?