We are working on a validation script and know how to set things up. Currently we create validation scripts based on each customer. Of course we have to ensure that each batch/document uses the same fields but is there a way to decouple the script from a specific document class?
Then it would be possible to create an external script (with a Git flow) and roll it out for multiple customers. Currently we can only create one unique script per document class.
One way to decouple validation scripts from specific classes are field scripts. There's a drawback, though - field scripts are tied to one specific field; you can't access any other runtime elements (such as index or batch fields) via the API. There are some tricks to work around that, but as said - by default, it isn't possible.
I recommend creating a standalone function library and then reference it from your field or validation script. While this requires you to roll out said DLL to any station running Index.exe, this approach makes your DevOps life easier.