With "GSX menu" you mean the transparent window ? That's not a "GSX" menu, it's the standard Simconnect menu which is used by every 3rd party application with an in-game menu, like SODE, FSPassengers, and so many others.
This means:
- We don't have any control over it. We cannot control size, position, etc.
- The ONLY control you have over it, is the mouse to resize/move it and eventually undock it.
Nothing we can do about it and it will obviously affect any 3rd party application that use that menu, so it's not a GSX issue in any way, but it's just how FSX works.