Re: Strategy.... Have Stern create/improve new song mode logic? There's no sense of urgency while you're in a mode. Although you at least have the loss of your playfield multiplier as a penalty for draining. But it doesn't alter decision-making all that much.
See prior @ScoutPilgrim comments regarding KISS being song-heavy. There seems to be more value in using MB's as a safe way to progress/finish songs to get your PFx up rather than shooting for the MB jackpots themselves.
There's some strategic decision-making on which shot you choose to multiply, based on what song modes have left to play to maximize future mode scoring, or your next-up multiball.