Yes, I'm using the stack filter inserter. Of course, I could use the normal filter inserter, but that would mean losing A LOT of throughput because I move like a quarter the amount of items, no? And in that case I could just as well go back to my old, boring, non-smart setup.

I'm not quite sure if this is a bug, intended or if just hadn't been considered.
I wanted to setup my main train station like shown in fff #140 but encountered a problem. If you use the new circuit network options to automatically set a filter on an inserter, it will only ever work with the item ...