Received stuff. That 12V power brick sounds hollow never had that before.
In short right now I’m fucked, because to my understanding, the Add2PSU syncs with the 12V signals. I assumed that the fan connector on the PN50 had a 12V lead, but I just discovered it doesn’t have one. The highest voltage on any connector on the PN50 is 5V. And I tried to sync with 5V maybe but to no avail.
So now I have to do more thinking what I can do (that project has been thinking) and I posted a question on sff network in case somebody has a solution for me over there. At least the Gamecube adapter works this time.