i’m currently working on an update from TYPO3 v10 to TYPO3 v12 via v11.5. We have a large amount of custom extensions, which I am currently updating. We used to use our own custom viewhelper to include javascript and stylesheet files, which I am now replacing using the standard <f:asset.script and <f:asset.css> tags. See https://docs.typo3.org/other/typo3/view-helper-reference/11.5/en-us/typo3/fluid/latest/Asset/Index.html