Direct answer
Loader lag may be caused by hoppers, comparators, piston/dispenser updates or protection plugins, not by the shulker box item itself.
How to check it
- Measure active input items and output boxes over a fixed interval, alongside a spark sample of the same interval.
- Pause the upstream item stream to test whether the loader’s redstone clock continues ticking or only responds to arriving items.
- Test a single lane separately from a full array so you can identify whether concurrency or an individual device causes the slowdown.
Example: A stalled loader can be a throughput problem instead of a CPU problem. If 1,000 input items arrive but fewer are stored, validate collection and overflow before optimizing redstone.
What to change
Prefer demand-driven redstone to idle clocks when practical; remove redundant observers, duplicated transfer paths and overflowing inputs. Keep throughput data for comparison.
Software and version notes
Changing hopper timings or disabling movement events can alter loader timing and plugin protection. Back up schematics before rewiring and test for item loss or double-processing.
Verify the result
Run a full-box cycle with the same item type and rate, verifying every item is stored while TPS/MSPT remains stable.