Compact and UPS-friendly 1x1 loaders. Works with train cargo wagons, circuits, filters, and modded belts from Bob's, Krastorio, FactorioExtended Plus, Space Exploration, and Ultimate Belts.
Chutes are removing from machines/chests at 3.75 items/s, but appear to be loading at 15. The belt is going slow, the degrees/s are the same... I have some other mods so I can check vanilla+Miniloader if you want
It's known, but probably won't be fixed. Attempts at rough fixes have in the past caused all kinds of issues with the loaders sometimes being too fast, and sometimes being too slow, depending on subtleties of inserter hand movement timing. A reliable fix would be too expensive in terms of UPS and number of active entities.