Thanks for the input, this is useful.
Back to rclone, I found a way-around using toolbox. So, for those in the same situation: create a toolbox (toolbox create, toolbox enter) and then you can use the rclone script. You may need to install fuse.
It's not really working at the moment because it doesn't seem to actually mount the remote, but that's another issue, so we can close this one.