Hello,
For Google Drive case, that is running under the dual stack now. when I using the Web page to upload files that go through the IPv6(for sure, my PC is running under the dual stack too). If FU support IPv6 then it can resolution DNS name into IPv6 address and transfer/upload file via the IPv6 connection. For my case, I have two NIC on PC and I define one NIC for IPv6 traffic only, another is for Ipv4. then I am easy to separate the traffic flow.
For the modern s/w that should support IPv6 now, another s/w I used that is MiniPony that is well support IPv6 now ...
If you have time, you can study it as the new feature ....
Regards,
Cody.