I went and tried a save with 0.17.56 and it had the same behavior. I must have been hallucinating the filters in the earlier version. I'm sorry and thank you.

This save game is from my sandbox build that I build under 0.17.41. When I was building it in particular the stack filter inserter at the bottom of the train loop would support a filter of all of the items not in the "outpost" stations about half way up the loop.

If you can run this under 0.17.41 ...

I am not sure if this is a bug or feature, but it is a change in behavior.

Previously, at least in 0.17.41 the filter on a filter inserter or stack filter inserter was not size limited like the manual filter was if the circuit network was controlling it. As of 0.17.66 (and maybe a few before that ...