Topic on Extension talk:JsonConfig/Flow

We are wondering whether it is possible to configure JsonConfig for using the local wiki as a source of the values for Wikibase properties with type 'tabular data'. Our current configuration is

$wgJsonConfigModels['JsonConfig.TabularContent.local'] = 'JsonConfig\JCTabularContent';
$wgJsonConfigs['JsonConfig.TabularContent.local'] = array(
        'namespace' => 486,     
        'nsName' => 'Data', 
        // pattern for page name
        'pattern' => '/^[A-Z]*[a-z]*\.tab$/',
        'isLocal' => true,
);

but this does not work as desired. Wikibase still searches for *.tab pages in commons.mediawiki.org rather than in the local wiki.