What is a true peak meter used for?
The Meter is an RMS meter used to measure audio signal loudness, expressed in dB. RMS Response Time, Peak Decay Time, Max Hold Time, and Infinite Hold controls are available to change how the readings are displayed. The Meter is capable of up to 256 inputs.
Should you use true peak limiting?
Instead of letting the true peak limiting process deal with remaining true peaks in the output, it's even better to prevent high true peak overshoot in the first place. The best way to minimize inter-sample peaks and distortion, is to use oversampling.