Hi together,
I got a very nice and fast and concise answer from Martin at Kontant Lab, perfect service, very happy!
I hope it is ok to put this here to close the thread:
(...) This connector is placed on the PCB mainly so that the HammerPWR can also be used for quick connection to the system without the need to connect busboards via WAGO terminals, or for a quick test of a module, at the same time we use this connector to test the HammerPWR during output control.
With the 16-pin IDC connector, there is a small 3-pin jumper that can be used to switch whether the +12V voltage from section "A" or section "B" will go to the output of the IDC connector (...)
Cheers, Ron