IMO an air/fuel gauge can provide useful information during tuning as one piece of the pie but for day to day, mile by mile monitoring exhaust gas temperature is going to provide better information and an indication what load and potential damage you are doing to the motor.
I think it has been well established that with the '93 & '94 it is going to run lean with the TRD supercharger without additional devices such as water/methanol injection, rising rate fuel pressure regulator, ignition timing control and piggyback engine controls