Currently using a Visibility Volume means anything in the volume pops into view the second you step inside the volume, even objects that are right up against the edge of the volume. There’s no decent way to avoid this unless you have a lot of empty space with zero objects between the areas you want to use Visibility Volumes on.
I suggest we have a “fall-off range” setting similar to sound emitters, except that’s the range at which it loads in objects inside the Visibility Volume. That way you can control the view distance, so to speak. Alternatively, give Visibility Volumes two volumes, one inside the other, with the outer volume being the load distance for the objects inside the inner volume.