OutFiler is a file browser inside 3ds Max that replaces the standard save, load, save selected, merge, import and export dialogs with a folder tree. It lets you find folders quickly, keeps a history of your movements through them with back and next buttons, and offers a recent list and favorite paths for quick access to working scenes.
The browser saves and loads scenes and objects, and can merge objects by layer. It works with other supported formats such as FBH and OBJ. You can copy and paste paths, and assign hotkeys to copy and paste objects into another 3ds Max scene or another 3ds Max window. Operations run in the background, so you don't need to wait for the interface to update.
The developer also notes a related thumbnail issue: the 3ds Max installer fails to register MaxThumbnailShellExt.dll, so MAX files can show the product icon instead of scene thumbnails in Windows File Explorer. That DLL sits in the 3ds Max root folder from version 2014 onward.