I have done this, but it's pretty buggy.
If I search the post URL, I get 0 comments. https://imgur.com/a/Ec3GxO0 (Image from the search result so you can see I'm searching the lemmy.world URL as when clicking, it redirects to the lemm.ee URL)
If I search one specific comment's URL, I get one comment. https://imgur.com/a/gxIuUIu
So by this logic I would have to specifically search all comments to get the full content on one post? Doesn't seem reasonable.
That...... is ridiculous. Already, subbing to another instance's communities is unintuitive.
This will never become a reddit alternative if it's so finnicky!