Trouble with instanced static meshes

Yesterday I encountered a phenomenon that fascinates me-- generating a voxel field, by use of perlin noise, in Magica Voxel. Yet, a 120x120x120m voxel field is not optimised enough to run in UE4.
Recently, I’ve been learning to use instanced static meshes and attempting to create equations to place them via the most optimised blueprint coding, for example to create circularly instanced meshes along a radius.
For such randomised placement of voxels, though, I could not devise an equation. I have instanced a 1x1m plane (as to not waste unnecessary geometry) in a very primitive fashion (see screenshots), though I cannot help but think there is a much quicker way - such as using forloops. I know how to instance a 30x30 field of instanced meshes; but how could I do this in an optimsed manner whilst still incorporating forloops as well as accounting for the height variation? Or, if not, is there a perlin noise operation I can use in UE4 to procedurally instantiate these meshes rather than typing in their individual coordinates? I hope so, because manually typing the coordinates for all of these planes has quickly become a tedium.