When you’re using LiveComponents, they are assigned (by you!) a static id which uniquely identifies that component on the page. If you take a look at the LiveComponent docs and scroll down a bit you will see the following:
Two live components with the same module and ID are treated as the same component, regardless of where they are on the page. Therefore, if you change the location […] it won’t be remounted.
What this means is that LiveView is smart enough to send down a minimal diff notifying the client that a LiveComponent has been moved to a different place in the DOM, so the client can move that entire subtree wholesale without the whole thing being sent over the wire again.
The above does not apply to normal components, which would be sent again in full.
I do want to point out that you show a lot of concern for morphdom in your post (in the title, even), but your main concern should be the diffing that happens in LiveView before the diffs are sent over the wire. The morphdom part is really just a “final step” that you shouldn’t concern yourself with too much, as it’s plenty fast unless you are passing in truly huge diffs (in which case you will always run into wire problems first anyway).
