Cornering Speed
Written from a fighter pilot viewpoint. When applying to a transport, there are going to be additional factors to consider such as control hinge moments, wing bending moment, and control system design. (For Airbus FBW, all such decisions have been already made for you.)
With the nose buried downward, and with concern about hitting the ground, you would like to achieve a minimum radius turn, but without tearing the aircraft apart.
The minimum radius turn is generally achieved where max AOA and max allowable G meet on the performance curves.
You can consider using up some of your safety margin when planning what G level to attain. Then look up the performance curves and determine a cornering velocity based upon your most probable gross weight.
Below cornering velocity, you can slightly improve performance by accelerating slightly and pulling into buffet. Above cornering velocity, you must slow down to improve turn performance and meanwhile avoid going beyond your max acceptable G (without a G meter).
Knowing your cornering speed is strictly emergency knowledge and would be used solely to ensure you are not completely out of the ballpark in your pull out efforts.
No doubt, the test pilots and aerodynamics guys can flesh this out better. As I recall, the F-4 cornering velocity was 420 knots. You definitely will not want to be anywhere near that speed when you pull out in your transport.