Yep, there once was. And there where too many aabb, sphere, and similar methods that I got rid of them already some time ago and only kept those needed. aabb() is still a method of the VoxelCluster.

I'm using the following rule: everything like position(), orientation(), etc. is in worldspace. Everything somehow accompanied by "local", "grid", etc. is in object space. so yes, the radius() needs a scale-multiply.