Maybe a migration tool can be difficult to implement, but looking at ACF, the possible solution to this could be implementing a function just to recheck the fields inside each group and make corrections on metadata. A button on the page that list the groups could start this tool.
Workflow to migrate content could be:
This is my idea, I want to listen your opinion, maybe you already have a simple solution to this.
Welcome to the Advanced Custom Fields community forum.
Browse through ideas, snippets of code, questions and answers between fellow ACF users
Helping others is a great way to earn karma, gain badges and help ACF development!