Longingly wanting legacy NSCollectionView insertion behaviour

The legacy NSCollectionView grid has some really simple behaviour when dragging items around in the grid. When dragging item(s) to a target location, the proposed drop location would animate slightly ("parting the Red Sea of adjacent items" as it were) for the proposed drop. A bonus: there wasn't a vertical insertion bar.

I would assume that behind the scenes in the legacy implementation, the NSSpringLoadingDestination protocol and the view's animator instance were used to make this happen..

I managed to partly mimic this behaviour with the new NSCollectionViewGridLayout (via the aforementioned protocol/animator) and it's almost working. But I'm giving up on my approach as I can't see a means to obscure the blue vertical insertion bar right through the center of my items. That happens during my drag session when I propose at NSCollectionViewDropBefore operation (in my validate drop method) while returning anything but NSDragOperationNone.

I do see that there's a layoutAttributesForInterItemGapBeforeIndexPath method on the new layouts; that might work, but I don't see any means to avoiding the insertion bar highlight.

Does anyone know how to easily get this legacy behaviour with the post-OS10.11 NSCollectionView API?

Did you ever get legacy animation effect working for an NSCollectionView using the NSCollectionViewGridLayout layout? If so, can you share the code? Thank you.

Longingly wanting legacy NSCollectionView insertion behaviour
 
 
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