And I wonder if there's a 0-with-a-slash in the downloadable version of the font, enabled with an OpenType stylistic set number or feature or something, or if that zero-with-a-slash is just something custom the Airbus folks do internally.

According to the Github issue mentioning in a sibling comment:

We designed the two zeros having in mind the slash one to be used in alphanumerical sequences, and the normal one to be used in numerical sequences. > > You can find it in the ‘private use area’