By default, this alternative display is triggered from the 50th keyword entered into the system. As is normally the case, this value is a constant that you can therefore modify to suit your own customised needs: _MAX_MOTS_LISTE
This constant can be defined in your config/mes_options.php file (refer to The mes_options.php file)
Example:
// display the keyword search field as soon as there are more than 10 keywords
define('_MAX_MOTS_LISTE', 10);