Hi Martin,
thanks for your reply. Sry it took me a while, but I was able to run the Flow on another machine with an i7 8core in the meantime. Of course, now it works just fine, so I'm strongly assuming my i5 machine was just too weak (what I find quite weird). If you still want to have a look at the flow, I attached it to the post.
I'm still welcoming any discussion about that.
Cheers,
Manu