I had 2 seconds to go for another kp when the last tournament was awarded and blew that up.
Something has changed, usually I log off, before tournament ends (to avoid stream errors).
In my country forum someone mentioned, they add the KP when you log in, so I investigated it in last tournament. I had roughly 10 minutes to complete the next KP. I waited that time and logged on afterwards, the one KP were there and the KP reward was summed up on top of it.
Same seems to happen for AW, but I'm not sure on that.
+1 for the idea, I would love to choose on my own when its time to receive my reward from tournament (not only the KP).