Fixed columns with renderType => textTable?

Question

i have a custom content element with a bodytext field. The renderType is set to 'textTable'

$GLOBALS['TCA']['tt_content']['types']['myElement']['columnsOverrides']['bodytext'] = [
    'config' => [
        'type' => 'text',
        'renderType' => 'textTable',
    ],
];

Backend shows the visual table editor with one row and one column, columns and rows and be added and deleted.

I need a visual table with 2 columns (editors are not allowed to add more columns) and flexibles rows.

I tried this but it doesn't work

$GLOBALS['TCA']['tt_content']['types']['myElement']['columnsOverrides']['bodytext'] = [
    'config' => [
        'type' => 'text',
        'renderType' => 'textTable',
        'cols' => 2,
    ],
];

Thanks Steffi