Hi, TheAdventurer64,
My name is Artem, and I'm Ruslan’s teammate. Thanks for your kind words!

I will gladly share with you our reasoning on the indoor facilities. We see the matter like this: there are two ways for its mapping according to OSM wiki (https://wiki.openstreetmap.org/wiki/Indoor_Mapping#Tagging_proposals):
-  the tag you mentioned “highway=corridor” 
-  the tag combination “highway=footway+indoor=yes” (https://wiki.openstreetmap.org/wiki/Guidelines_for_pedestrian_navigation)

In the United States many buildings are mapped with tags highway=footway+indoor=yes. At the end of this page (https://wiki.openstreetmap.org/wiki/Simple_Indoor_Tagging) you can find different examples of mapping indoor features. Therefore, we consider this method of tagging to be quite appropriate.

We also take into account the OSM routing: (https://wiki.openstreetmap.org/wiki/Guidelines_for_pedestrian_navigation)
In the Simple Indoor Tagging model, pedestrian ways can be added to indoor areas and used by a routing engine.
So we changed the tag highway=corridor to highway=footway+indoor=yes for the ways located inside the airport buildings to ensure correct route building for pedestrians. Currently the tag highway=corridor is not injected for OSM walking routes. Perhaps we are missing something and the tag “highway=corridor” is more appropriate here. In general, we don’t change the highway corridor anymore based on our current flow. We are grateful to you for opening the discussion and will take your possible reversing our edits with understanding since highway=corridor tag is also acceptable in OSM. Thanks for your contribution!

Best regards, Artem
