TYPO3 Core

At now you can use &overrideVals[pages_language_overlay][description]=test to override the default values in TCA by Create oder Edit a Record
This function only hide TCA fields but it not override the value.

Solution:
\TYPO3\CMS\Core\Utility\ArrayUtility::mergeRecursiveWithOverrule($formData['databaseRow'], $this->overrideVals[$table]);