Hello, I'd also like to ask for this feature, since behavior of G-SYNC is quite inconsistent from my experience. It usually works fine but when I alt-tab to desktop and return back to the game, it sometimes won't activate back. But the bigger problem is that whenever I update nvidia drivers it totally breaks G-SYNC functionality and I have to spend good 30+ mins trying to make it work again. Therefore, I always keep using nvidia's indicator from CP, but that thing is so huge that it seriously breaks the immersion.
I own G-SYNC laptop and also G-SYNC external monitor, so I'd help you with testing as much as possible.
By the way, Martin, I'm also from Slovakia, so I could even help you in real-time using phone, if needed.