HELP! Trying to create 30km landscape, it crashes all the time.

Hi to you all,

This is the first time I am posting usually I get all my answers right away but this time I am a bit desperate.
First of all, It is for a personal project.
I am trying to create a map that is supposed to be 30km.
Now, I tried using a single 8K texture and then scaling the terrain but then the resolution is too low and sculpting fine details around the city is not possible.
So I delved into world partition.
In World Machine I used the tiled option and I have exported oh so many versions of tiles of varying resolutions from 505x505, to 8129x8129.
If I try to load anything beyond a final resolution of 8 km, (no matter how the individual tile resolution is), unreal crashes, not when selecting the tiles but when importing them, claiming that it got out of memory.
Now, I have seen some huge landscapes, so obviously I am doing something wrong, for it must be possible to create a such landscape, but I don’t know what it is.

My computer is an MSI Trident X with 32G RAM, an i9 10900K, and an RTX 3080.

Exactly what am I missing? What do I have to do to have a 30km landscape, or at least 20km?

Thanks in advance and if there is anything I have not explained properly let me know.