Hi. Let's assume you are this man and you want to put a One-way and an Extractor into pipes. You stand like he, put Extractor into the left pipe and One-way into the right one. Then look at them and notice in which directions they are returned. The One-way is returned in your direction, but the Extractor contrary. It looks inconsistent and not intuitive. I think they both should be returned in the same direction when they were placed from the same side. In my opinion the One-way placement method is better, because if there is a chest you have to destroy it first, collect lying items, put an Extractor, again place the chest and put items into it to make this works. If Extractor placement method is the same as the One-way placement, you not have to destroy the chest.

For a better understanding of this problem: