Do buff reapplications count toward Freya's pushback?

Two scenarios:

• If all 4 hits of Freya's ult apply/reapply Nightmare, does it push the enemy back 4 times, or only once (ie 12% or 3%)? Which is to say, do reapplications of an already applied buff count towards the pushback?

• If Viper's ult lands both the Atk- and Spd- simultaneously, does this push the enemy back twice or just once (ie 6% or 3%)?