Docs for innodb_flush_method are incorrect

The docs for innodb_flush_method state:

1. the option is deprecated
2. if set to O_DSYNC then the new options are set to ...
3. if set to fsync, littlesync, ... then the new options are set to ...

The docs are here:
https://mariadb.com/docs/server/server-usage/storage-engines/innodb/innodb-system-variables#innodb_flush_method

— for point 1, deprecated

The option isn't supported. So the deprecation claim is wrong as deprecation means it won't be supported in a future release but is still supported today. Alas, I have a separate issue open for the misuse of "deprecated".
https://jira.mariadb.org/browse/MDEV-33958

And from reading source for MariaDB 11.4.10, that option is defined with the PLUGIN_VAR_READONLY flag, meaning it cannot be set and is hardwired to O_DIRECT (confirmed via testing as well). If you try to set it to something like fsync, then MariaDB will quietly ignore it.
https://github.com/MariaDB/server/blob/main/storage/innobase/handler/ha_innodb.cc#L19196-L19199

— for points 2 and 3, if innodb_flush_method is set to ... then new options are set to

This text is misleading given that innodb_flush_method cannot be set. It is hardwired. The values for innodb_log_file_buffering, innodb_data_file_buffering, innodb_log_file_write_through and innodb_data_file_write_through are the same whether I set innodb_flush_method to O_DIRECT or fsync, which is:
innodb_data_file_buffering OFF
innodb_data_file_write_through OFF
innodb_log_file_buffering ON
innodb_log_file_write_through OFF