I would say that he needs more A time in order to feel tired enough to go down for a longer nap. Have a look at the following link:
http://babywhispererforums.com/index.php?topic=64158.msg476652#msg476652So tomorrow, try extending it about 10-15 minutes and see if he sleeps longer. Yes, the climbing on his knee could be contributing, but let's try the A time extension for 2-3 days and see if that works.
You're going to also run into the quandary of where to squeeze in that catnap, or he might refuse to take the catnap at all. We actually just dropped it ourselves after weeks of 2h45-2h50 A times. We're now at 3h, and can successfully just have 2 naps.
To combat OT at bedtime if he doesn't catnap, you might have to put him down to sleep earlier--if he's a 12h sleeper normally, this should be okay. If he's an 11h sleeper (like my kiddo is), then you could also go ahead and offer the catnap, but push bedtime back by an hour--we did a 13h day with an 11h night.
It could also be that he's turned into a snacker since he's BF more often. If he's not dehydrated anymore, I would go back to one feed per EAS cycle. That way, you know he's getting in a good feed and can last through until the next E time.
HTH!