Hey again Necner,
I now see much clearer what you are talking about, and we always appreciate this type of feedback and effort our users provide to help improve the engine. This image will be helpful when creating the feature request! I will create a feature request to have this implemented for the Foliage Tool. I can agree and say this would be really helpful for those who are using a lot of different static meshes as foliage, and would like to organize/control them a bit more.
Thank you again for the information as it helps us improve upon the Engine and its future releases.