So the operational g-load could either be 7.33g or 5g?
With the inference of a limit load of 7.33g, then for the piloting community the aircraft would have been limited to 5g for flight testing.
However, IMHO (a gut feeling and not much more), a research aircraft might have been limited to 4.5g if load measurement was not the primary objective of the tests: – mainly swing wing aerodynamics?
Early flights may have had even lower limits, like any new aircraft type, and if the total flying achieved in testing is low, a research aircraft might never experience the aircraft limit; - pure supposition (5 years with RAE).