I earlier posted a video of the Robocop modified with the game ending hidden switch mod. I got asked about that a lot, so here's the first public variant of the mod.
It consists of a 3D printable frame that goes where a coin rejector used to be. It has a switch that reaches into the coin return slot. Lifting the coin return slot's flap triggers the switch, which again is wired parallel to slam tilt. Bye-bye, abandoned 4 player game with 2 balls played.
On the more technical side, this fits the standard mechanical or electronic rejector coin doors. The extra huge ones (like the ancient Mars rejectors) aren't supported.
The design principles were simplicity, ease of build and install and cheapest possible construction for mass builds. After the prints, this thing can be built in minutes. The frame was designed with #FreeCAD
You can get it here:
https://www.printables.com/model/1460088-pinball-game-reset-mod
https://www.thingiverse.com/thing:7182962