Lots of stuff from the Asset Store come with textures for their editor gui, image effects or gizmos that won't ever be used anywhere else. I'd love to have a toggle in the import settings (or maybe mark a folder) to hide textures or other assets.
When I'm selecting a sprite for my button I don't need to see all the miscellaneous textures used in some plugins' node-editor.
Who needs to see all the textures for a character? Those are normally assigned once to a material and I always assign them by dragging from the Project view anyways.
Why would I need to see all 64 blue noise textures used by the Post Processing asset.
Unreal lets you hide and show engine content, I love that. Treating plugins and assets from the asset store that way would be great!