When you have a NSDiffableDataSourceSnapshot you can perform a reload on any section/item.
Whereas when you have a NSDiffableDataSourceSectionSnapshot I can't do any reload.
I would like to refresh a specific item because after creating the snapshot I need to trigger the reload via collapsing the section and then expanding it again in order to my cell registration set the cell properly with the updated tag.
In my opinion, collapsing and expanding an item which own child items doesn't produce a refresh of cells. With value type data (struct, not class), to refresh a parent item, you need to delete and insert the parent, then recreate the child. To refresh a child, simply delete and insert a value which contains a modification of the index data for the snapshot. If the modification doesn't change the index, the cell won't be refreshed.