I just tried purposely to use all of the processing power and was able to, but only by making ridiculous dual amp chains with lots of effects. For example I'd make one, and then try to add a second reverb or pitch and it would exceed the limit. Reverb and pitch use the most processing power. But who needs two reverbs in a chain? So it's a non-issue.
As for the sag, bias and advanced controls for the cabs, I have all of the latest firmware etc. Where do I access the new control parameters? I cannot find them.
Thanks!