I think there’s absolutely no way the cracks are from the torque of the rims.
Looking at the H5xLeaf you can see the cracks are produced radially around the hub, and right where the plastic is making a sharp transition shape wise. I’m guessing it’s from the hub expanding more than the plastic can and the shape of the plastic creating a weak point.
I think it’s from temperature changes, too, but it just sits on the table in my house. One day I picked it up and all of these cracks had appeared out of nowhere.
Again no performance change, can’t feel them with my fingers, seems internal.