Hi! I’d like to suggest a change to how the "U-shaped Sorter" works. In the image, you can see that I’ve connected three U-shaped Sorters—each with a filter—to the output of a waste sorting plant.
The issue is that it has an internal buffer; when it fills up, it stops sorting the other items because it gets backed up. My suggestion is for it to function like the "U-shaped Balancer":
even if one output is full, it should continue filtering the other products as long as there are other available outputs. I hope I’ve explained this clearly—thanks for your time!
I have 1,000 hours of playtime, and this is something that’s been bothering me lately, as it limits some of the plants I’ve been building...

I don't think I see how this would work. In the examples with balancers and connectors, there are multiple inputs with only one product type each. If the output of gold scrap backs up, then the input of gold scrap backs up as well, but the inputs of iron and copper scrap can continue fine. But the sorters only take from one input, so when it gets full of gold scrap, then any gold scrap on the belt going into it can't move forward. Iron and copper scrap that are also on that same belt can't skip ahead of the gold so they're stuck too.

In order for copper and iron scrap to keep coming out of the waste sorting plant when the gold is backed up, the waste sorting plant would have to stop outputting gold scrap while continuing to output the others. If a new system were put in place that connected the waste sorting plant with to the u-shaped sorter and had the sorting plant stop outputting gold when the sorter couldn't take anymore, then the sorter would just fill up its own buffer of only 180 pretty quickly and the situation would be the same again.

It would work something like that; in this farm example, the soybean storage is full but the wheat isn't, yet because the "U-shaped Sorter" is full of soybeans, it won't let the wheat pass through. Farms and some structures like the "Research Lab" have a function that deletes unconsumed items; the "Waste Sorting Plant" could have something similar.