Design pattern for "Reference Counting" assets?

Hi,

I have a component that builds BVHs.

While only a few mb, they are big enough to make large scenes pose a problem for the source control system when serialised as part of a scene.

I know the correct solution is to save these as an asset, and store the reference. I don't want to bother the developer with handling these assets though.

The BVH's will not be shared. They are quick to build. (And while I know its common, I don't think they should be shared between meshes, as there are many cases in which meshes may be modified on a per object basis.)

I'd like it to appear as if the BVH were a member of the instance of the Component saved with a scene/prefab, when in fact they are stored in a separate file.
When the Component is deleted, reset, the editor crashes without saving, etc, that file is cleaned up.

Is there a design pattern that does this?