Question about Instantaneous Turn Rates

I am trying to get a grip on how instantaneous turn rates are impacted by altitude. It may be that some designs have better ITR than others at lower altitudes while others have better at higher altitudes.

I think that for instance, the EF-2000 and Rafale have excellent high altitude, high speed instantaneous turn rates due to their inherent aerodynamics and high instability.

Am I wrong? Am I right? Would appreciate your thoughts.