I'm glad you mentioned Hainsey. I've been doing research on him and a few other OL prospects not talked about here much.
Robert Hainsey - According to PFF, he looked like a natural center at the Senior Bowl. He showed out on multiple positions across the interior! And the Rams love converted tackles so I think he's in play towards the end of the 3rd. He may not have the feet for OT but he does for IOL.
David Moore - He also played all 3 interior positions at the Senior Bowl and looked good at center per PFF.
D’Ante Smith - He's raw but per PFF he had one of the highest win rates at the Senior Bowl. Since the Rams typically look to redshirt OL he's a perfect future LT candidate for Round 4.