Everyone else? I assume that you’ve posted this somewhere besides here. Like I tell people I work with… Nothing is impossible. Possible is limited only by the amount the client is willing to spend.
But you are right, it will probably take a great deal of work. Basically you’re going to have to look at every field in the old system and figure out what might be compatible in the new system and put a filter in place for every field. In the long run it might be more time and cost effective to build an new site and repopulate all the data manually.
On the other hand, I was curious so I was looking. I can’t seem to find much information on this magic fields plugin.
You might also try WP All Export and Import. There is an ACF add on. You could probably use these to export the data from the site and then import it to the ACF field. But I still don’t think that would be an easy task.
Sorry I couldn’t be more helpful
