Played a few games on Deadpool last night at a friends.
A few things to note regarding the playfield multipliers.
We were both able to aim for and achieve the multiplier intentionally quite a few times.
In multiball, one ball hit the standup and ricocheted up the ramp, while at the same time another ball went up the right ‘lock’ ramp the ‘traditional way’. This awarded 2 playfield multiplier advances.
Not certain of the exact circumstances of how this happened:
Player 2 started playfield multiplier, then mini deadpool multiball (may be the other way round?), then drained out of multiball but the 2x playfield was active and running for the rest of his ball - it never timed out, nor did he hit anything to obviously extend it. He eventually got it up to 4x, at which point it started timing out.