I used 2 jars of 6.5 oz pb2 in a stout i did and it was overkill. The beer was cloudy do to the pb. it tased good but each bottle had a good amount of pb left in the bottom of the bottles. Next time im gonna do one jar of pb2 and maybe some crushed peanuts.
ive done up to 9lbs of dark lme. I also steeped specialty grains tho too. I dont see why you coundnt but i would steep some other flavors in there or it would be pretty basic.