At least on Windows you can add an existing steamapps directory on the download settings page. If you can add custom library locations on Linux, I'd probably tr

At least on Windows you can add an existing steamapps directory on the download settings page. If you can add custom library locations on Linux, I'd probably try making a copy of my Windows steamapp library, adding that directory in the Linux client and running repair for all individual games. That will at least save you from having to download everything.