I see and understand what you all have done, but, if one of them breaks, none will work after the break point, right ?
Shouldn't it be safer tu use some kind of "connection" where all the grounds connect and then a single cable to the IPAC ?
Something like this:
IPAC
__________________|__
|oooooooooooooooooooo|
|____________________|
| | | | | | | | | | | | | | | | | | |
Buttons