Do you have the Y80 manual? They are posted in the eAhora section of this website. I have the same controller on my XC100 but rarely ride in PAS0. There is a table at the end of the manual on PAS levels and their respective power settings, which includes PAS0. So I would think throttle should be available at 0.
Also did you know you can configure up to 9 PAS levels? The default is 3, which works fine for me, but the flexibility of this controller is very good. The table I refer to above explains the range of power you can assign to each level. I set mine to PAS1=55%, PAS2=75%, and PAS3=99%.
However, I can't recall if there was an option to set PAS0 power level. Never occurred to me since I don't use 0.