There are so many stupid smelting made by total morons including Nilaus end game smelting. I hate the pilers, they are overused and stupid, coz you are unable to select what is pilling up and if you dont have science they will block the path. This is single belt solution and it wont clog. So perhaps something usable for a change. DO NOT UPGRADE BELTS, SORTERS they there are for a REASON, just  upgrade smelters. I am not combat person, so you have to figure out the next stage. There are some numbers in the game like 360,270, 7300, 1440 and so on...  Single segment yiedl 7,2k for 1:1, half  output for 2:1  for sipmle plane smelters, build for plane in 3,6k per minute at 1:1 smelting, for magnets and crystals needs to be expanded for few smelters in such pattern, do your math. Simple? Piler sorters wont BLOCK your path if you dont have researched.  And that piler sorter upgrade research is one of the most important to get b4 white science.
Add a lube for maximum output, no lube 25% drop, for 2:1 smelting output is half. Design for maximum belt output. Change spliters for copper/bricks/silicone/titanum etc. You can add segments up to 6 for 1:1 and for 2:1 7 times if you figure out the splitting.
There is a reason for breaking to the segments with 12x2 smelters, unfrotuatelly that game wont uphold the math and in single belt wont go for 5760 and it will clog...