I was right in front of Axe-Edit III (duh) so I checked it out. I was shocked to discover that the Fat parameter in the Wah block is usually set to 8.70 in the Factory presets (!), altho there are some with different values. Fat value can range from 0.00 to 10.00, so 8.70 is close to 50/50 dry/wet. I might have to do some testing, just to see what would happen if Fat was set to 0.00 in a preset where it was previously set to 8.70.
Anyway, long way of saying that you were right, 0 is not the default.