It would be a simple SSH connection (actually 10), so on the host side it doesn't matter, would work with credentials as well as ssh keys set up correctly on the client (WN). But from within WATCHNET there seems to be no option to put in credentials. So I will give the keys method a try another day. But I expect it to be a puzzle game as well if it will work at all...
I thought maybe another forum member has already come across this, with all those cheap little boards and sensors out there.
I already have a solution to cover this project using another show control software, I think I'll focus on this one for now. Would have preferred using WN though.