Direct answer

The Leaf 1.21.1 reference lists async.async-locator.enabled and threads. The option concerns locate/structure-search processing; it does not automatically speed up ordinary chunk ticks or every plugin command.

How to check it

  1. Confirm the exact Leaf branch and whether its generated config still contains an async-locator section.
  2. Reproduce slow structure searches or map generation, and distinguish them from terrain generation and disk I/O.
  3. Monitor CPU and errors while using the feature with any structure-finding plugin that operates on the server.

What to change

async:
  async-locator:
    enabled: false
    threads: 0
  1. On a matching branch, keep automatic worker sizing first. Test a single supported structure search with the feature enabled and disabled on a disposable copy.
  2. Avoid a large explicit thread pool when chunk workers, region work or JVM tasks already saturate the machine.

Software and version notes

Compatibility and safety

The public reference documents Leaf 1.21.1, not every 26.x build. Do not paste this example into a newer config unless your generated file and branch-specific documentation confirm the keys.

Verify the result

Compare locate latency, CPU, search correctness and any task exceptions. Restore the previous configuration if results regress.

References