The best use of shot multiplier is on the left orbit while super pops/ pop jackpot is lit as it adds 500k to the pop jackpot. So if you stack a 5x shot multiplier with 2x playfield it will add 5mil to the pop jackpot which can then still be collected at 2x for over 10 mil. Or if you get brave try to build up and collect with the shot multiplier as well!