doc: clarify options for single customization hooks thread

doc/api/cli.md

@@ -898,7 +898,8 @@ changes:
 > [`--import` with `register()`][module customization hooks: enabling] instead.
 
 Specify the `module` containing exported [module customization hooks][].
-`module` may be any string accepted as an [`import` specifier][].
+`module` may be any string accepted as an [`import` specifier][]. This option
+has no effect on worker threads.
 
 ### `--experimental-network-imports`
 

doc/api/module.md

@@ -113,7 +113,9 @@ changes:
     `initialize` hook.
 
 Register a module that exports [hooks][] that customize Node.js module
-resolution and loading behavior. See [Customization hooks][].
+resolution and loading behavior. Registering modules that export [hooks][] only
+has an effect on the main thread. All worker threads inherit the customization
+hooks chain of the main thread. See [Customization hooks][].
 
 ### `module.syncBuiltinESMExports()`
 

doc/api/worker_threads.md

@@ -1008,7 +1008,10 @@ changes:
   * `execArgv` {string\[]} List of node CLI options passed to the worker.
     V8 options (such as `--max-old-space-size`) and options that affect the
     process (such as `--title`) are not supported. If set, this is provided
-    as [`process.execArgv`][] inside the worker. By default, options are
+    as [`process.execArgv`][] inside the worker. `--experimental-loader`
+    and `--import` with `module.register()` calls to contribute to the hooks
+    chain do not have an effect on the worker threads. These options affect
+    only the configuration of the main thread. By default, options are
     inherited from the parent thread.
   * `stdin` {boolean} If this is set to `true`, then `worker.stdin`
     provides a writable stream whose contents appear as `process.stdin`