I am not sure it suits your use case, but it is possible to keep the Rclone "installation" on an external drive. Rclone is portable in the sense of "cross platform" but also in the sense of "PortableApp". It does not need to be installed other than to download and extract the program files to a folder. It can also keep its configuration locally, see Documentation. This means if you have an external drive where you keep your data, you can keep Rclone on it too:
- Download Rclone for Windows and for Mac and extract to a folder of choice on your external drive. Rclone is single executable so you only need the one file from each download (i.e. rclone.exe on Windows).
- Move your existing configuration rclone.conf to the same folder (or create a new empty file with that name to start from scratch).
That's it. Now you can run rclone commands from the folder where your executable is, it will read and write the configuration file in the same folder. So when this is on an external drive you will get the configuration along with you.
Note 1: I am not familiar with Mac, so there might be restrictions that makes this approach not work as it does on Windows.
Note 2: There might be security considerations regarding passwords stored in the configuration file, when this is on an external drive you carry around with you. Then you could consider encrypting (password protecting) the configuration, see Documentation.