2 1x1x1 cubes do actually intersect

I was playing around with my voxel engine and discovered that if 2 1x1x1 cubes are next to each other they intersect.
https://playground.babylonjs.com/#JDQS13

comment out line 26.

an interesting discovery.

Now I’m left wondering if there is any where to see the number of meshes a mesh is intersecting.

That’s because they in fact Do intersect. The adjacent faces, vertices and edges are aligned at the same position, so they are touching. You can use an incredible small amount of padding, and don’t forget to force computation of the world matrices when you do intersection tests before running the first frame:
https://playground.babylonjs.com/#JDQS13#1