What sort of things would this enable you to do? I’m thinking the most useful thing would be get different voxel spacings for some particle objects. If that was the only benefit, it might be simpler to allow the spacing to be set on a per-object basis in the atmospheric. Having multiple atmospherics try and communicate with each other seems destined to cause headaches.
If we had multiple objects with different spacing values, I’d have to loop through each of them each time I went to sample along the ray. That is somewhat easier than trying to compute an entire ray and then combine the results afterwards.