I can see a case for it since TK counters won't be open yet to re-check until about 3 hours before the flight. This is my most common reason for wanting interlined bags on long layovers. Then I'm free to do whatever I want on the layover without worrying about lugging or storing my bags. In the case of 6 hours, I'd likely head to Hong Kong station and get some food and a beer in town.