i have similar problems but i have any results. i would like update the slug (post_name) with wp_insert_post_data based on my field my_baseline
Step 1
– Create new post
– fill field text as “my_baseline”
Step 2
– Save your post
i finaly found simple solution to use $_POST[‘acf’][‘field_myfieldid’];
the better way with to use json to convert acf_field name to acf_field_id