Foundation & Strong Arm apparently help against the pushback roll, but since strength DEs got neutered this season those don't seem to be as important. Protector is ok for LTs, but I don't think it's necessary by any means. I don't really think there are any SAs that are essential for pass blocking, but Cut Block & Get Low are supposedly good for run blocking. For pass blocking, it's more important to have huge amounts in strength & agility, along with the proper VAs.