Hello,
Thank you for your progress report!
Regards,
Kino on behalf of the Sia Foundation and Grants Committee
The Pinner.xyz portal is now working for uploads and is using renterd for the s3 buffer storage as well.
If the foundation needs an account to test anything, they can DM over established channels for a login as I do not wish to have an account abuse on the system before I am able to handle it 
. However registration simple, and no billing plugin is currently active.
I will be focusing next on getting billing services online.
Thanks.