I have following code:
$fields['location'] = [ 'type' => 'combobox', 'label-message' => 'ainut-app-location', 'notice-message' => 'ainut-app-location-notice', 'options' => self::$locations, 'default' => isset( $defaults['location'] ) ? $defaults['location'] : '', ];
If the form format is ooui, the input acts as an input field with dropdown to select values. This is useless. If the user cannot search, I could as well use regular dropdown (I don't allow values outside from the provided list). In the regular format the suggestions are at least filtered down to match the input, which is good.