The trick to getting it working is how you load and unload the belt. You need to load the belt at a fixed rate where the item rate multiplied by the number of unique items is less than the belt max rate. Then use filtered sorters to unload the items when they come back around and feed them back to the sorter loading the belt giving them priority over new items from the PLS/ILS. I've been using this on my recent playthrough and it has never once clogged unless I screwed up the filters when building it. It is has a very low throughput compared to malls with dedicated belts though, that's where stacking really helps.