Yeah, I've played a few that had the difficulty jumper set...I wonder why they didn't just make it a dipswitch, so operators didn't have to go soldering their PCB's?

Anyway, I tried the peach pattern on the regular Midway set in MAME (playing your video side by side with it), and at about 39 seconds in on your video, when you're going down the long vertical channel, on the Midway set, you're following Pinky and Clyde comes up at you, making a left turn under the tunnel, but you run into him there. On yours, Pinky is behind you and Inky and Clyde are up above the monster pen. I tried it a couple times to make sure I wasn't doing it wrong and it did the same thing every time. Here's a screenshot at the death:
Here's the same spot using your pattern on the "Atlantic City" ROM:
Also, it looks like they may have messed with Pinky's AI in that Atlantic City ROM...I notice when I put it in the hiding spot right above where you start on the Midway set, if I face up, he circles the pen, if I face left, he circles around the rectangle to the left and above where you start...on the Atlantic City one, he goes around the bottom T with Blinky no matter which way I face.
Oh, checked out your site...looks good!