Exactly i have no idea how long it can take. I also provided additional documents on 27 August and after I uploaded, my Gckey account shows "Additional documents you have provided are uploaded". After I uploaded documents, in next few day I also noticed a ghost update.
In first week of september, I raised a webform to know the status, VO replied that they are currently conducting a acertain background verification. Likely they are verifying the additional documents I provided. So one month has passed and I didnot recieve the decision.
One of my friend got his approval 35-40 days after he sent additional documents. His approval came on same day he saw review of additional document in his Gckey account.
If you attached it through webform, then you should not worry. They receive everything we send through webform. You will see it someday in your Gckey account