On the 92, Out 1, Out 2 and Booth do not have the same output gain. But at 0DB on the meter and gain set to max on Out 1, it give a bit above the standard +4DBu, which is good enough to clip the input of most Eq/processor. And you still have plenty headroom left.
It doesn't need to be louder than this. I really think it's a deliberate decision. In fact I prefer this point of view VS another mixer who can give MORE juice AND clip any Eq, Processor, Limiter input preamp THEN give distortion BEFORE the amp.
Well my 2 cents.