Direct answer

The historical use-brain-ticks-only-when-lagging switch applies the adjusted villager brain interval only during lag, rather than continuously. It is not a global AI-disable option.

How to check it

  1. Find brain-ticks, use-brain-ticks-only-when-lagging, and lagging-threshold in the configuration generated by your exact build.
  2. Count active villagers, measure AI tick cost with spark and record trading, work-site use and pathfinding behavior.
  3. Check current Purpur docs/changelog: these historical options may change or disappear between versions.

What to change

  1. If the option exists, test changing it only together with a clearly understood brain tick interval.
  2. Avoid aggressive throttling on live trading halls or iron farms without gameplay testing.
  3. Restore previous settings if villagers fail to work, restock, trade or navigate as expected.

Software and version notes

Compatibility and safety

Historic Purpur docs specify this conditional switch; current public documentation has changed and might not expose the same keys. Never paste an old example into a newer Purpur configuration without confirming generated keys.

Verify the result

Compare villager response times during normal and lagging conditions and confirm expected trading/restocking behavior.

Related topic: Purpur Villager brain-ticks Explained. Compare the two guides when choosing the right diagnostic or configuration step.

References