I’ve been looking into this, and it’s not something that’s going to be possible. I was looking at the plugin that you’re using for the export/import, I think you meant this one https://wordpress.org/plugins/widget-importer-exporter/. It seems to be a well maintained plugin and it appears that the author is actively supporting it. My suggestion would be to contact the plugin author. I see that there are hooks in both the import and export functions. I’m not very familiar with the plugin, but it may be possible for you to create a filter that will add the ACF fields to the export and then another filter that will let you import the ACF fields, but you’d need to get more information from the other plugin developer on how those filters work. It that’s not the plugin you’re using let me know what the correct one is.
