XY-scaling of the Landscape Actor to Match the Grid

I am viewing my landscape actor in an orthographic bird’s eye viewport (wireframe mode), and I use a power-of-2 grid system instead of the decimal one.

I want to scale my landscape actor in such a way that, if I cut a square hole with the visibility tool, that hole will be exactly 256uu x 256uu.

But because the viewport always shows the LOD transitions of the landscape, I can never be sure what the “actual” positioning of the landscape vertices are, so I don’t know what what value to scale X and Y by.

What should I do to get around this problem?

EDIT: Nevermind. I figured it out by just placing a 256x256x256 BSP cube in the level and using the 3D viewport in wireframe mode to see how fine the tessellation was. Turns out that scaling the landscape by (128,128,100)% gives you a grid spacing of 128uu. Now I feel dumb.