When you submit a CNC part for examination, our production team may reach out to you with feedback to help make your parts manufacturable. On the part page, click on the 3D viewer button. You'll see the badge that indicates the number of DFM comments left by our production team.
To respond to DFM feedback, reach out to us via the chat message box on the bottom right corner of the page. Mention the name of the part and the question you're responding to (the number of the question is fine) followed by your comment.
This makes it easier for us to relay that feedback to the engineer who is quoting your CNC parts.