So in other words you will be one of the last to finally go over to XP 11.....while you find a....."feasible" way to interface?
It's not really a question or a race to who's become first or last. It was right not to support X-Plane earlier, because it was really missing too many features to be considered mature.
So, at each and every release, we read again all what's required to read in the SDK, and while we see it's definitely improving, it's still missing lots of crucial features we require, especially for something like GSX, which requires some kind of UI.
And, right now, developers requiring an UI, are presented with 3 equally disappointing choices:
1) Use the existing API, which will result in the outdated and soon to be abandoned old style UI
OR
2) Create an interface from scratch, drawing gadgets like drop-down boxes, list boxes and other UI elements, directly in OpenGL, which is really not a very clever way to waste valuable development time
while waiting they'll complete the new UI APIOR
3) Waiting until the new UI API will be completed, which of course is the most sensible thing to do.
In the meantime, we'll probably release some scenery in the mid-term future (sometime in 2019, I guess), which doesn't have all such requirements.