Distributed ACF Relationship fields still showing IDs from parent site

[tim-plimsoll]

Describe the bug

I have a custom post type with a matching ACF field group on both the source and target Wordpress installations. When I pull a post to the target site, the relationship field appears empty in the UI, but if I open the database and look at the field values, I can see it has data, but the IDs are the ones from the parent site. It would be preferable if the plugin would check to see if the IDs in an ACF relationship field reference posts that have also been distributed, and change those IDs before committing them to the database.

Steps to Reproduce

• Install ACF and Distributor on two Wordpress sites, Site A and Site B.
• Configure Site B to be able to pull posts from Site A
• Create an ACF field group for posts on Site A, and a relationship field for posts in that field group.
• Export this ACF field group from Site A and import it to Site B.
• Create a Test Post A and a Test Post B, with the relationship field for Test Post B pointing to Test Post A.
• Create Test Post C, Test Post D, and Test Post E on Site B, to ensure the next available ID is different.
• Pull Test Post A from Site A to Site B
• Pull Test Post B from Site A to Site B
• You will see the relationship field on Test Post B either referencing the wrong post, or empty.

[tim-plimsoll]

My specific use case involves both ACF Relationship fields pointing at posts that have already been distributed to the target site, and ACF Relationship fields pointing at media library items attached to the same post I am trying to distribute (to be used as a gallery on that page). I mention this because Distributor would need to keep track of the distributed media library item IDs as well, and ensure that mapping exists before correcting the ACF Relationship field on the post that just brought over all the new attachments.