Opie is sooooooooooo cute.
Your sanity and Opies is important. Letting Opie play with others and on the cat tree under supervision isnt going to hurt anything. For someone who has had a broken leg Opie sure doesnt show it by his upside down impression of a monkey in a cage.

I think when vets come up with these great ideas, they should try it out themselves first and then see if its the right thing to do. LOL