For instance, this one (link to a post to !memes@reddthat.com): https://reddthat.com/post/20260613
Pasting it in your search bar should give you this kind of results:
You can then click on it to access the post from your instance (in this example, lemmy.zip: https://lemmy.zip/post/16918691)
I’ve been using a GreaseMonkey script to do that, I can’t find the exact one I used but there’s a bunch that do posts too, and extensions.
Maybe this one? https://greasyfork.org/en/scripts/469273-lemmy-universal-link-switcher
That looks to be it, I recognize the long long list of instances in the code.
Is it the best? Don’t know but it works well enough.
In my experience, yes. Definitely the best one.
All the other ones I tried are much worse.