Direct answer
Leaf can skip some map item data updates when a map does not have a CraftMapRenderer. This can help image-map workloads, but it may also stop vanilla-style map contents from updating as expected.
This is a Leaf-specific configuration option, not a general Paper or Folia setting. Confirm the key is present in the configuration generated by your own build before changing it.
How to check it
- Identify whether the server uses filled exploration maps, an image-to-map plugin, item frames with rendered maps, or a combination.
- In a test world, compare a newly explored vanilla filled map with a plugin-rendered static map before any configuration change.
- If map updates are a measurable cost, profile while players generate or display those maps.
What to change
- Find the exact skip-map-item-data-updates-if-map-does-not-have-craftmaprenderer key under performance in your Leaf configuration.
- If your gameplay needs vanilla maps that track newly explored terrain, do not turn on a map-update skip without a functional test.
- Change only this option on a test server and keep a copy of the earlier value.
- Copy the current configuration and note the previous value before running a controlled test.
Software and version notes
Published configuration path: performance.skip-map-item-data-updates-if-map-does-not-have-craftmaprenderer.
This is a map-renderer-specific trade-off, not a universal packet or chunk optimization. Plugin map renderers can have different behavior.
The archived Leaf global YAML documents the 1.21.1 branch; newer official examples differ. Do not copy an older default or missing block into a current server without verifying that release.
Verify the result
Explore new terrain with a vanilla filled map, inspect displayed item-frame maps, and check image-map plugins. Revert if any map that players rely on stops refreshing.
Keep the A/B test results, server build, config diff and rollback notes together so the result can be reproduced.