Proof external URL does not allow attachments
I'm testing the proof feature to see whether it suits my use case. When a proof participant receives the email and clicks the Review Proof button, he is taken to the proof as an external URL in full screen mode, which is great. However, in this view he can submit comments but cannot send attachments. It seems like attaching files to proof comment is only possible if the user opens the proof from the sheet.
Am I missing something here or is my undertanding correct?
Ideally, I would like the external URL to allow proofing participants to send attachments if necessary.