How to override column through TCA in custom CType that uses flexforms

Question

I am trying to override the label of the crop field of a sys_file_reference in my custom CType. This is what I have so far (added to myext/Configuration/TCA/Overrides/sys_file_reference.php):

(function () {
if (is_array($GLOBALS['TCA']['tt_content']['types']['mytype'])) {
    $GLOBALS['TCA']['tt_content']['types']['mytype']['columnsOverrides'] = [
        'myfield' => [
            'config' => [
                'overrideChildTca' => [
                    'columns' => [
                        'crop' => [
                            'label' => 'XXX',
                        ],
                    ],
                ],
            ],
        ],
    ];
} })();

I am pretty certain this should be working since I verified it does work on textmedia but it is not working for my custom CType. Am I missing something? Could it be the fact that the CType is generated through flux and therefore the fields are in a flexform? Maybe this requires a different approach?

Thank you

Answer 1

Thanks to @Julian Hofmann asking whether the CType might be generated after the TCA override I thought about moving the overrideChildTca into the flux config itself:

<flux:field.inline.fal name="myField"
 config="{
  overrideChildTca: {
   columns: {
    description: {
     config: {
      type: 'passthrough' 
 } } } } }" />

'passthrough' hides the field.