Different Runtime World Partition grid for different foliage made by procedural foliage tool?

Oh, well, it is not “just few trees”, it is a huge forest 2x2 kilometers (well to be fair 2x2 is not just forest, but I think maybe 2\3 of it or near so).
I took a look in the documentation for HLOD - I don’t think it is for the case like this. There are hundreds of trees.