Previously I was waiting 7 months for my decision. If I had sent the original passport, residence card, employment contract, lease agreement, I would have stayed practically without any documents while waiting for the decision (from my experience about 6 months). A notary is an expense, a time, and it is challenging to balance the dealings with working time.
At the moment you can only send documents by post. When we restore the direct customer service, you will be able to show the originals of all documents sent to us by post (in response to our request or on your initiative). We strongly advise against sending your passport by post - you should present this document in person at the office when we start our direct customer service. Personal appearance and fingerprinting are necessary to start the procedure, so even sending a set of documents by post makes it impossible to begin the examination of your application. We recommend that you add any new documents by post, particularly in those cases where the application has been corrected, and evidentiary proceedings are ongoing.