KA manager at Siem Reap tried to tell me that I wasn't entitled to the "courtesy" of through-check from KA to a separate QF booking because I had 4 hours between flights in HKG and therefore had ample time to collect my own bags. I had to get the policy on screen, read it out to him, and say that the policy mentions nothing about MCT and that he should through-check me.
After a minute or two of argument he agreed to try, and after 15mins of him tapping away at the computer it was all done - real resistance was probably because he was lazy or clueless as to how to do it.