All the airframe structural cases (for whatever manoeuvre) will be cleared as not causing any overstress on the aircraft (or pilot) by setting an upper limit on the particular manoeuvre entry speed.
The aerodynamic (stability and control issues) will have been dealt with by normal flight test iterative procedures.
The technical challenges of such manoeuvres actually centre round the engines. You have to keep them running and you must not overstress them with the gyroscopic forces that arise at high rates of aircraft rotation in pitch and yaw.
Avoiding compressor stall due to intake flow distortion at large angles of attack or sideslip requires two things. To quote former MiG-29 chief designer Michael Waldenberg these are a “good basic engine surge margin” and a “suitable” intake. Sadly, an explanation of what is involved in both these topics needs more than a few words. However there is more to a “suitable” intake than is apparent from a casual external inspection.
The overstressing of engine components in high rate manoeuvres first raised its head back in the 1970s when the USMC got the bit between their teeth on the Blot flop air combat manoeuvre during which a Harrier can be made to pitch at rates exceeding 90deg per sec. This turned out to be very much more than the engine had been designed to accept mechanically and was also way outside the AvP970 design standards for military engines at that time.