I don’t use Google Drive or Dropbox or iCloud or Box, which I suppose makes me perfectly Internet Qualified™ to comment on this topic, but the thought occurred to me that if one wished to dedicate an external drive for cloud storage purposes, one might be able to get away with mounting the drive itself (which I’ve called /dev/disk99 here) as the cloud storage directory, for example:
mount -t apfs /dev/disk99 ~/Library/CloudStorage/
Don’t try this at home, folks, unless you’ve spent enough time with Unix filesystems to understand the implications. For instance, you would almost certainly want to unmount the volume from the /Volumes/ directory first. There are opportunities for data loss! But it is much more likely to work than symlinks.
I will try it if I get some time, but I’m on a product release push so it might be a month or more.