Maybe the idea is too trivial or not needed by anyone but I was unable to find it online.

For me, it's quite useful because I deliver uranium to my nuclear plant by drones so I need some buffer on the plant side but I don't want to keep a full container of uranium there. So I want to limit it to 3 stacks and sink everything above that amount.

The solution is quite simple. All you need are Industrial Storage, one Smart Splitter and a lot of Coal (or any other item to fill up the container). This solution doesn't limit flow at all and provides 780/m input/output. Just fill the container with coal and leave as many slots empty as you need.