Most Motorcycle tires have about 80% of the dry grip when wet. I know you are not getting the answer you are looking for. It seems most Burgman riders are not Joe Rocket riders. I have never measured the angle.
But I know that when I was accident avoiding on wet pavement and TRYING to go harder left than my normal cornering, I hit the center stand, levered the rear tire up, low sided, then the tire re-caught grip, high sided me into the side of the RED pickup truck followed by my very own Burgman smacking me from behind, squishing me.