Is it necessary to pin the entire landscape (in world partition) to build the Nanite data?

For example, if I have another non-unpinnable (because of the Water) landscape which takes very much memory and each extra cell can lead to crash? If, for example, the first mentioned landscape will expand, I will need to have two 8x8 km landscapes pinned, to build the Nanite data (which itself takes much memory)? Or is there a sideway?