I don't know alot about your motor but couldn't you drain the oil/drop the oil pan to get a better look and see if there's any noticeable damage/metal shavings in the oil pan.

If you know for sure it's rod knock it's really just a matter of time before it goes. Did you ever plan on turbo-charging the KA or eventually doing an SR swap? If so, looks like now is as good a time as any to build the motor or swap it. If you planned on just keeping things relatively stock you could probably source a KA bottom end(or even complete motor) from someone who swapped their 240. Best of luck either way.