Editor slows exponentially when selecting an instanced static mesh in viewport that has a large number of instances

Editor slows down exponentially when spawning in a large quantity of instanced meshes.

1. Download and unzip linked project:

[Link Removed]

2. Open linked project>FFT_Test1.umap
3. Select "RandomLand" in viewport
4. In details pane, set YMax and XMax to 100
5. Once the change takes effect, type "stat fps" into console command.

Note: If you deselect the instanced meshes the fps returns to a normal state. It only drops if the mesh is selected.