I agree with the patience aspect as well.
At Level 2, I don't recall the rope climbing involving the more difficult legs out technique. I remember the inner thigh rope burns back then! These days though the rope climbing is legs out. And they do progress doing this skill OP!
My daughter was out of the gym for about three weeks and was given a conditioning list which she did not really stick to. When she returned to the gym there was a 1-2 week period where she really felt it by not keeping up with her conditioning.
If locations are fairly close to I-95 and the Florida Turnpike the trip between Port St. Lucie and Jupiter is not so bad but I know if you live close to the beach getting to the highway alone can take 20 minutes not counting a drawbridge on the Intracoastal stopping you in your tracks.
Have him help clean up around the house....keep the muscles active:)
Seriously, I wouldn't push any more than he is willing to do. They all need a break....