Hi,
Thank you very much for your excellent report! Much appreciated.
I have looked into your example, NANWALEK, and you are right, but there is a but 
ASOBO/MS uses the airport code KEB (the IATA code) for Nanwalek instead of PAAW. You see this too: when you look in the MSFS Flight Planner, you see PAAW, but you can´t use it because it´s not “included” in MSFS for this airport code. You can only use it with KEB and not via PAAW.
Here from the MSFS Flightplanner - you don´t find KEB, you find PAAW, which also we offer:
That is exactly the issue with duplicate airports. We are currently comparing only the airport codes, and when they differ, we “create” the airport, as in this case.
The PKEB was a bug and is fixed from the next AIRAC on. We have improved the comparison from 2605 on, but that does not mean you won´t still find any duplicate airports. We have only a limited number of possibilities to check this. Please report it again if you see any duplicate airports starting with the next cycle.
Thank you,
Richard