I just got the new rclone version v1.74.0. It got a new gui command (rclone gui) that runs a web based gui. Its awesome. You can interact with all kinds of storage in it and edit all of your local configs. Since it is web based, you can also use the gui on a remote server and simply tunnel the port via ssh to your local machine.
And what does that do?
Scans through and indexes the directory/files and gives you an interactive ncdu-like interface, so you can browse files and directories and easily see what takes up space.