I honestly would go with Hammer arm. Higher power is always important in playthroughs, plus exploud has low speed so it won't really matter as most of the time it won't outspeed. Screens are not common in playthroughs either.
EDIT: I realized that you are playing singles and battle tower, and now I can understand you doing both because in competitive screens are a bit more common, however, I would still recommend Hammer Arm