On my side
Check Graphical Capabilities returns instantly, a new window should pop up.
On the other hand you don't need that. It only returns what extensions your gpu supports.
For Development itself it is not relevant, you could only need that when developing against a particular gpu extension, but then you have to ensure that your code properly checks whether that extension is available or not.
So are you trying to achieve something special or were you just curious and clicked that?