check box overlap / colliders in edit mode

I'm writing an editor script that places objects, so to make sure they do not overlap, I would like to check that.

But since the physics simulation isn't running in edit mode, I can't use colliders. I need to place objects fairly close, and some are long and thin, so a rough approximation with bounds fails if they are rotated.

Is there a relatively easy way to check? I'm fine with 2D checking since they are all placed on a flat surface, so if there's a simple solution for rectangle overlap in 2D that would help as well. Or a trick to rotate bounds that I missed?

I checked for other solutions but the most common answer is approximating with sphere.overlap, which doesn't help me (I need to check boxes and I need to be relatively exact).