If you received the same email that everyone else got, then it did say the following: "You will not be able to upload multiple supporting documents to your application. Please upload any attachments as one document to your profile."

Whether you received it or not, it would be best to make one document and then sign in to update your resume. In the past, this feature hasn't worked and it always shows your old resume. Hopefully they have fixed that.

The good news for you is that most people are under the assumption that the initial screening is done by an outside company without any weight being given to LORs.