As an interim solution would it be possible to check for the presence of a particular file (within FSX folder) that would imply one of your detailed sceneries for a specific airport is installed (Geneva Cointrin for example)?
No, it's not (I would told you that, if that was possible), since the file that enables YouControl it's the same that enables some scenery objects, docking systems, GSX customization AND YouControl so, there's no way for you to tell YouControl it's available or not, just by its presence.
Of course, you can just keep a list of known FSDT sceneries (that will have to be kept updated when we release a new scenery) and a file that has to be checked.
In this case, you should check the fsdreamteam\Couatl folder, inside you'll find several folders with the scenery names (it's usually the ICAO, but not always), each one containing a file named __init__.pye
, if that file exists, that means the scenery has at least some special interactive scenery objects OR some docking systems OR a YouControl menu.
Not all FSDT sceneries have a YouControl menu, KORD doesn't have one for example, and the Hawaii1 and 2 are "multi-area" products, so each one will handle two airports, so you'll have to handle this special case too.
I think it's a bit cumbersome and not automatically reliable, because we might change this at any time, so it would be MUCH better if we publish an FSX variable to check as soon as any airport creates the YouControl menu, so this will always work, will not require any checks, will never be broken by new releases and it will be trivial to code too.