How to handle br/hard_break in slice

I would like to remove the usage of hard_break (backward compatible) and split text into paragraph if there are hard_break(s) in between, I know there is a parse rule closeParent can do the trick, while some cases in paste cannot be handled, resulting in [TextNode, hard_break, TextNode]

seems one of the way is using appendTransaction and do what Enter do, but this will leave steps records and affect old contents, I want to avoid this

it seems hard to handle it in paste slice? any suggestion I can generally handle all the cases?