Mmmm ...
Why are you asking this ? ....
If you are temperature limited, you are temperature limited at whatever Nr you choose .... you may well be MORE temp limited if you use 102% because you are demanding more speed from the Nf section.
Use of 102% Nr is generally to allow the pilot more inertia in a rotor system to counter Nr droop should a power unit fail during a critical flight regime such as Cat A departure, Winching or external load operations.
