Not sure if you got an answer to your cruise question, but I'll try to give you my spin on it.
When the cruise is set on TBW bikes, and the grip is allowed to find it's own rest (you let go), it returns to zero throttle. If you roll forward to negative throttle, it will disengage the cruise.
The throttle is controlled by the ecm and the stepper motor on the throttle plate, as well as the injectors. This motor is not as quick to react as the old throttle system (it has a lag), so if you dis-engage the cruise and then roll on, the slower you do this, the more the bike will decelerate, but the quicker you do it, the farther you will have to turn the throttle before your throttle grip position sensor = throttle plate position and then they will increase asa normal throttle would.
If you leave the cruise engaged and choose to accelerate, you will have to catch your grip postion up to the throttle position being held by the cruise. How much you have to twist it depends on the speed you are set at and the load your bike is under, which will be different for bikes and conditions.
Hope this helps.