As noted in the KVS Tool User Guide, the [Awards/SkyTeam] Method provides Availability on a per-trip basis. The Award Availability shown applies to all connecting segments.
Indeed, it is a limitation of that Engine.
We have confirmed that 3 C Award Seats are currently available on CZ 628, but only 2 on CZ 671.
How did you confirm that only 2 C are available on CZ 671?
I'm not sure I get the whole "married segments" concept but it seems what you are saying is the the AF engine is getting tricked into showing 3 seats for the NRT-SHE-ICN routing? And the blank line on KVS (which per your suggestion is the same as the first line, i.e. 3 seats ARE available) is an artifact of the AF bug?
"Our system will not allow it". I asked her if she could call CZ (i.e. suggesting what I believe is called a "long sell", I might even have used those words) - but she said they do not have any way of checking inventory with CZ. I am not totally clear on what the agent was saying. Perhaps she meant that only 2 seats were available, period. I also asked if she could book the 2 and we could figure out the 3rd, but she thinks that by doing so the third person's LAX-ICN and ICN-LAX transpacific C legs might get blown away. (There seems to be reasonable return inventory but I confirmed that now no seats show available on the outbound flight).
Other than this the agent has been very very nice, in fact she called me back like she promised (unlike reports to the contrary on the AZ boards that the call center agents never do so). She also complimented me on finding the itinerary and has given me till Thursday to find something else
I need 3 seats in C from Tokyo to Seoul Apr 15/16 with at least one leg not on Korean Airlines (nonstop KE inventory is available, but AZ claims stopovers are not permitted on Single Skyteam Partner awards).