After reviewing two games which are currently being burned in at the company side by side for testing and potential needs for bulletproofing, I would pause before installing a shaker motor. Potential for cold solder joints on the main playfield coil transistor driver board. My opinion as a technician. Anyone that has owned games like Roadshow can relate to what I am sharing.

I am not against Houdini, AP, or shaker motors.

I cannot confirm that all final production boards are from the Multimorphic proprietary design.
This would be best answered by AP, as I did not have time to review any schematics, or if they were available last week in the shop.

I did see that all I/O control boards were Multimorphic P-ROC (dipswitch modifiable), but these are all SMD electronics with no mounted components, and are not the concern. The PCB I am referring is directly in the middle of the playfield, which operates all primary feature coils, right above the pop bumpers. In the past, pinball manufacturers placed this type of board in the backbox for a reason.