ScriptHandler.php should be automatically upgraded

[gagarine]

The project should not upgrade himself?

Typically after #539 people have to manually copy/past the files?

[leymannx]

No this whole project is just a template. If you want to get the latest changes you need to git diff and adjust manually. I know this might be frustrating but it's a chicken-or-the-egg problem somehow and can't be easily fixed. We first would need proper releases for that (#425). And then maybe have some mechanism that at least notifies you the next time you composer update about possible changes to be done. That's a lot. For now it's won't fix, I'm sorry.