For sharing data between different Zorro instances, it would be best to store the history in a Dropbox or Google Drive folders.
What will be the best practice? Are there any performance drawbacks in doing so?

In the order of easiest but least reliable, to hardest but most robust:
* Dropbox / Google Drive
* Host an ftp server and use ftp functions
* Host a REST server and use http functions

You need to understand that Dropbox and Google Drive synchronize files on their own terms and not your terms.

What about hosting history files directly in S3 bucket and mounting the bucket to the local file system?

Sure, why not?

Actually, it turns out that Google Drive has a REST API that you can access with Zorro’s http functions. That can work pretty well.