I use WPC coin doors in my System 11 machines that I bring to the Northwest Pinball and Arcade Show. I do this because I want the headphone jack in the dollar bill slot plate. I have a bridge wiring harness but it's kind of a hack because there's no latching switch. I simulate the latch by wiring it such that holding one of the red (up/down) buttons is equivalent to latching the center switch. It's NOT obvious to people who don't know what to do and are used to the usual System 11 configuration.
I have several ideas to eliminate the bridge wiring harness. One is building a custom board with WPC coin door connectors on one side and System 11 connectors on the other. I'm too busy with other things to deal with designing this board so it's very low on the priority list. I also have some latching DPDT switches that I want to replace into one of the center red buttons on the four button assembly but also haven't made any progress on that front due to the aforementioned other things to deal with.
For your wiring issue you should consult the System 11 manual on the page "cabinet wiring". It shows you exactly how the coin door switches are wired. Note that the coin door switches in System 11 are on the switch matrix whereas in WPC the coin door switches are dedicated grounded switches.