Hi Johnny,
You said: does the anagami wear out his kamma vipaka in the Suddhavasa abodes and enter final Nibbana there?
One does not have to wear out his/her kamma vipaka to attain nibbana. Nibbana is attained via understanding / comprehension. So i think it is right to say that he will achieve that understanding in the Suddhavasa realm like Lal has mentioned.