Blade Weaving Bonuses Bugged or Not Displaying

I just tried Amumu with Spell-Weaving & Blade Weaving but 3 stacks of BW didn't change the base AD display. I'm not sure if the actual damage was affected or not.

I also don't know or it is not possible to see detailed champion stats like Armor Penetration, Magic Penetration and several others which can be useful when itemizing vs specific armor/mr values.