Have you considered a crate instead of an xpen to help keep him confined? Rory came up limping, and we weren't sure why, but the vet prescribed antiinflammatories and two weeks of inactivity (crate rest, basically). After two days, she showed no signs of pain, so I stopped the antiinflammatories (with the vet's permission) since I didn't want her to overdo it thinking she was better than she was, but I did the crate rest for the full two weeks.
The good thing about a crate is you can move it from room to room with you, pick it up and put it next to you on the sofa, set it on the nightstand next to the bed, etc. It's really easy to poke your fingers in there too. We used lots and lots of bully sticks and Himalayan chews too, but most of the time she slept. It was hard to leave her in there, but I knew it was for her own good.
Rory is very, very active, but I know nothing compares to the energy of a puppy, especially Max! Max (and Cooper) is so lucky to have you! Just thought I'd mention the crate to see if maybe you wouldn't have to spend large amounts of time in the xpen yourself.
