Moodle core code reports, that accent insensitive search is not possible with PostgreSQL.

This is only partly true, as there a various approaches how to achieve this goal. However, all alternatives are dependend on the actual database configuration. This plugin relies on the PostgreSQL-extension unaccent and modifies SQL-statements accordingly.

There is no need for Moodle administrators to install this plugin separately. It will only do its job, if it is used by developers within their code. If developers use this plugin, they need to link it as dependency in their version.php. Hence, this plugin will be installed automatically if needed!