Cull by Distance from Point

Hi all,

I am attempting to use attractor points to remove bricks from a parametric system.

The idea is that any brick within a certain distance from the point(s) is removed, thereby creating an aperture. 

I have had some success, but I cant figure out why, after using ClosestPoints to subtract from the original list of plane origins, I can't seem to get the same plane orientations - the X axes seem to be random after these operations, where before they were oriented to the surface normals. This seems to happen in a middle swath to the right of the attractor point, and some planes are multiplied and rotated in place. 

I have tried using Distance, but couldn't figure out how to cull the list of origins based on that parameter.

Thanks for any help!