Breaking: #86492 - Removed stdWrap support for config.additionalHeaders¶
See Issue #86492
The feature to use
config.additionalHeaders has been removed due to
an incompatibility with page caching.
stdWrap cannot be used anymore to manipulate additional headers set via TypoScript.
Any TYPO3 instance that uses this feature, which has been introduced with version 9.0.
For the time being there will be no TypoScript based solution for dynamic HTTP headers.
Consider implementing a PSR-15 middleware to add advanced logic for additional frontend response headers.