Hook into prefab import pipeline possible?

I have a bunch of prefabs (using nesting & variants) with a lot of instances on a big scene. I want to somehow post-process the resulting game object (optimize hierarchy), while leaving the source prefabs unchanged.

From my understanding of how prefabs work, they get imported (in a chain, if nesting/variants is used) just like any normal asset every time there is a change. So I wonder how can I modify/post-process this imported version of the prefab so the optimized version will get inserted into a scene? Is something like this possible at all?

I can of course make a Scene Post-processor script that will optimize the resulting hierarchy of the entire scene, but that approach is less efficient:

- It'll have to re-process instances of the same prefabs many times, effectively multiplying the processing required many times
- Unoptimized versions of prefabs will be loaded when working with this scene in the Editor

Thanks in advance.

 

For housekeeping purposes, it sounds like this was added in 2020.2
Prefabs: Added support for a Prefab post-processor.