Why are Landscape's XY Scale Uniformly?

I’ve been working on importing height-map data into Unreal and I noticed that the X and Y scale are uniformly handled ( X=Y). I’ve found a hack to modify X and Y independently by using the copy/paste feature in the scale ui widget. However, that only works for non-tiling landscapes. The Import tiling (World Composition) UI works differently and doesn’t use the same scale widget I believe, so can not set X and Y independently.

I’m just wondering why is the Landscape XY scale uniformed? Is it for performance, materials, etc? The reason I am bringing this up is because I am working with GIS data and using GeoTiles for height-maps and these are not perfect square resolution in meters. So I’m trying to figure out which approach to work with is to either manipulate the height-map data which can be done, but not the preferred choice, or modify/create import function to be able to scale X and Y independently.