Wrong.
The peroneal palsy is only associated with dorsiflexion, so it has minimal effect on the ability to run, cut, fight off blocks, etc.
The deficit is simply flexing the foot upwards before setting it down again.
The brace used for this has spring-loaded dorsiflexion, so it helps with that particular movement.
As I've indicated previously, the total function of the foreleg will be at about 95% if the peroneal nerve is 50-70%. As the neurapraxia improves to 80-90% (possibly by TC), he probably won't need the brace, as he'll be at 98-99% functional.
The knee is fine, the strength is back, there is no compensation or asymmetry of motion (already demonstrated weeks ago), and there will be no increased risk of reinjury.