Passing a getResource parameter in a chunk

You can try:

    $output .= $modx->getChunk($tpl, array_merge($scriptProperties,[
        'index-title' => $sectionOptions[0]['sectionTitle'],
        'flexgrid-cols' => $sectionOptions[0]['sectionColumns'],
        'limit' => $sectionOptions[0]['sectionLimit'],
        'flexGrids' => implode("", $flexGrids),
    ]));

This should pass all scriptProperties