A couple of quick follow up notes.
The Documentation already includes supported key codes in charts for the supported locale specific keyboard layouts. See under Docs, Input Devices, Keyboard Layouts for the PDF files that have these charts.
The docs team tell me that one should read this like a white list - they key codes shown are the ones you can map. So things not shown, notably the PAUSE/BREAK key, should be the clue that the game doesn’t support them.
Regarding the supplied Excel based editor tool and the ability to assign callbacks to physical make or break for a given switch and the ability to invoke callbacks with either or both of key up and down semantics: the device tabs for joysticks like Cougar or Warthog do not support that.
However, there is a “DX specifics” tab which can do this. The idea of this tab is that you can construct one or more lines for a specific switch and then paste those lines from that sheet into your key file as required. Yes, that means lines constructed there do not show up in the automated “output” tab so there’s a little more work to do to leverage what’s in the DX specifics sheet but… I was wrong to say that the capability is not supported in the supplied editor tool at all. My apology for the mistake on my part there.
I did add a to-do item for adding more defense in depth to the key file parsing code. This is at best 4.<thirty-next> though so not all that soon.