Your only real choices are premium pluigns, I prefer http://www.wpallimport.com/ and it’s export counterpart. Yes, these can be expensive, but most of them, if you buy the right one, give you lifetime support and updates. The one I use is a bit more expensive but it comes with an add ons specifically for ACF and WC.
And now for my honest opinion, export and import tools will not save you any time over editing the information directly in WP. Any time savings, as far as I’m concerned, is an illusion. When you take into account the time needed to set up the export, do the export and then do the import plus then inevitable time you’ll spend correcting problems because you made a simply typo in the data before you did the import, it is very likely that you’ll spend more time than you would have it you just opened the products and made the changes. But like I said, it’s only my opinion.
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!