That way we could immerse ourselves more by 'disappearing' the GSX menu completely and assigning button presses direct from our control surface via LINDA!! (Lua Variables)
This has been discussed already, there is an API in the GSX future, once the program will be completed with all its features (we are still missing de-icing, water/lavatory and gpu vehicles), but we'll not use anything that would require another 3rd party product to work, in this case would be FSUIPC to enable LUA access.
Instead, we'll use standard Simconnect features, which means addons for GSX without requiring to use anything extra than plain FSX SDK, and it would also automatically work over a network, which is another desirable feature. The Simconnect approach is also language-neutral because, as long there's a language binding for Simconnect (it's native C++, but I believe it's possible to use C# or Visual Basic too), one can use the language of his own choice, without having to be restricted to a specific language.
The recently released SDK from PMDG, for example, works in the same way, and that's the correct way of doing things, for a native FSX addon like this one.