Optimization options with `getLocalDataPaths`?

[j9t]

In debug mode, Eleventy returns lines like this (newlines added for better visibility):

…
2025-09-30T18:35:40.990Z Eleventy:TemplateData Using [ '.11tydata', '' ] suffixes to find data files.
2025-09-30T18:35:40.990Z Eleventy:TemplateData getLocalDataPaths('./posts/2021/guide-to-301-redirects-with-an-htaccess-file.md'): [
  './posts/2021/guide-to-301-redirects-with-an-htaccess-file.11tydata.js',
  './posts/2021/guide-to-301-redirects-with-an-htaccess-file.11tydata.cjs',
  './posts/2021/guide-to-301-redirects-with-an-htaccess-file.11tydata.mjs',
  './posts/2021/guide-to-301-redirects-with-an-htaccess-file.11tydata.json',
  './posts/2021/guide-to-301-redirects-with-an-htaccess-file.json',
  './posts/2021/2021.11tydata.js',
  './posts/2021/2021.11tydata.cjs',
  './posts/2021/2021.11tydata.mjs',
  './posts/2021/2021.11tydata.json',
  './posts/2021/2021.json',
  './posts/posts.11tydata.js',
  './posts/posts.11tydata.cjs',
  './posts/posts.11tydata.mjs',
  './posts/posts.11tydata.json',
  './posts/posts.json' ]
…

Information on what getLocalDataPaths does and needs seems scarce, but with multiple paths that don’t exist or that don’t seem needed, this output begs the question if individual Eleventy projects can be configured for better performance.

That is, are all the .js, .cjs, .mjs, .json look-ups or file generations needed—and if not, how could they be disabled?

At least on the surface, there seems to be potential for performance optimization (especially on large projects—thinking 10,000s of source files, the context in which I spotted this).

(If I miss something, happy to learn more as well—thanks! 🙂)